Larry, I think that Rosso Fuoco is correct (see Maserati list). I think the original color was quite a bit more orange than say, a 70's Ferrari (which had a lot more blue and then progressively added more orange during the 1980s in Rosso Corsa, then Rosso Corsa -6, then Rosso Corsa -9 as used in the F40). Seeing 8ma1074 (which had been at least re-topcoated, but I really think door jambs were original paint and matched) from these pictures looks very orange...I think just a very 60's kind of color. Very early Pantera may have been very close or same...

I'll have to look, a few years ago I looked at the paint mix (the balance of base colors) on Rosso Fuoco on maybe a BASF jobber website, and the balance of orange is really strong.    I went deliberately more blue...with Ferrari Rosso Corsa -6. Ferrari also has a Rosso Fuoco, their color is way different (very, very blue/purple)--Lee

That is the "small" book. Here is the larger one, showing 5 shades or red. As Lee has stated find a spot in the doot jamb or under carpet or under window rubber to scan the closest shade. The original Glidden Salchi enamel recipe no longer exist and even the build sheets do not specify which shade was used.

Here is another reference, Iso Grifo colors https://mycarquest.com/2011/05/iso-color-samples.html  Note, the sequence of the Iso colors is different from the Goose roll in that the metallics are separated from the solids, but in both cases add up to (5) red shades So if you want to go a really orange Rosso Dino (Ferrari name for probably what here is Rosso Aurora), or even the metallic, and still call it a factory RED, now is your chance Lee

Thanks guys, much appreciated, the car has been bare metalled (paint on their my guy says is modern) once before and they did a proper job by looks of it as can't seem (yet) to find various versions or red or another colour..  

Looks like they removed spine and door brackets when they repainted.  Screen is coming out soon to rectify some sketchy wiring so we may be able to see behind screen rubber or elsewhere.

It's interesting as it shares a garage with a 69 Alfa Duetto in Alfa Red (that car had its originally Duco paint sticker) and they are virtually identical in shade. Existing Mangusta colour is definitely not the orangey.

Larry, interesting that name Alfa Red, I glanced at Alfa colors and that red seems different from the ISO Grifo "Alfa Red..." Always something...Lee

So the intrigue deepens.  We’ve looked at what we consider to be hidden areas of the red and it looks to be the Maserati Fuoco and an Italian brand of paint actually lists this as Maserati De Tomaso red.
but

we’ve discovered gold!

in fact  it’s a very light area of gold like paint behind the dash and in corner of underside of roof behind headlining. Denis, your large wheel of colours doesn’t show a light gold but Lee the ISO wheel shows a light platinum ‘ champagne gold.

Now I really don’t want to go pay a stack of cash for the factory archive / build sheet records when all the previous owners I can trace (from 76) say the car has always been red.

do you guys know if below headlining and behind dash was painted body colour, primer or black? I’m now my car, a late 4 headlight car was one of the ones finished in Germany as has numerous features of those.

we’ve looked below spine, behind door mounts, underneath of screen and they all show red but my guy thinks they were painted when it was bare metalled.

...finding a "Detomaso red" is a pretty good sign...!   But I think I've been over every millimeter on 8ma1076, and didn't find a lick of gold (!) And even, under the headliner--no paint. What I saw was a use of a yellow primer, maybe a black sealer, and then color...The yellow was a flat, unsaturated color, very much like what I used in the 80's as an etching primer or if I remember correctly, also a BASF primer I used to like... Attached is the archeological dig on `1076--with 2 layers added in the 80's (the last an early 70's Porsche red my brother sprayed).  But another place that should be telling is under the felt in the trunk, see both the yellow primer before the blackening, also traces of overspray on the shock towers. I have a very fuzzy picture also of red on the interior frame of the A pillar where then leather was added.

See also pics from 8ma1074 wheelwell and 8ma1046 (which had original paint, and if you use your imagination enough shows the black color on top of the black primer, followed by the rather dirty/grainy blacking paint that (ok, this is getting obsessive ) heavier flat blacking paint (see the overspray on the vinyl edging trim...).  8MA1046 may have had some touchup under the front spoiler, but nothing on the rest of the car indicated the slightest touchup...

   I have lots of other pictures, for example under the leather trim that goes along the interior ceiling roof--just the yellow primer and a hint of red overspray.   Especially for your car, in 1976 its really unlikely that someone decided to do a color change and then hit also perform a complete disassembly, re-leathering and bare metal paint job to remove every speck on the car...And I'm sure most agree, DeT was not vigilant about hitting every spot right, there is just not a lot of attention on the car to corrosion avoidance or water drain holes (!) It seems most the car got nuked with undercoating, but paint everywhere else.

   So my suggestion, paint it whatever color you want Yeah, there are already plenty of red Mangustas, but as Dick Ruzzin points out, its a great color for the car...! Lee

So, saw car last week. As these pics show it looks like there is a yellow ‘ flat gold primer rather than colour. Ignore the brighter yellow that’s the tape we are using to mask off!

all evidence is pointing to the Maserati De Tomaso red we found! And I agree with Dick, they do look good in red!  Red it is

Although the yellow primer they used did give us a glimpse of a Giallo Fly potential!

thanks for all your help

...maybe because I grew up in the American midwest, but more likely because 40 years ago I was constantly working on a car---my favorite color for any car is 'primer...' So exciting to see the car getting completed. (And Yellow would have been my other choice...but after 8ma516 was repainted, all I know is that my car was originally red ).