Wow, what a brilliant video introduction of the Goose...absolutely beautiful. And the sound, geez the car feels alive. https://www.youtube.com/watch?v=hqHKUM3efRQ
I asked Dick Ruzzin (the one time I met him at the Concours Italiano in 2016, featuring the Mangusta) about the clear turn signals on his car...he said he just liked it better that way 
The clears were used for this lamp as reverse lights (that Carello lamp was used on just about every Italian car at one time in the 60's in some form or another).
As a US car, 8ma1028 as a Vin really falls into a 2-headlamp car, not a 4-headlight...So I'd be curious about other clues that it wasn't always a Euro car (English gauges may not be a help here, but whether there was a smog pump or rear marker lights may be a clue).
Btw, I missed the chance to identify the headlamps put on 8ma1046...and at 12k miles, they were probably the correct lamps for US 2-headlight cars. And knowing that they were probably a simple Sylvania sealed beam, on '1076 I went with a pair of genuinely old-from-a-Fiat Carello JODs...so even if not right, they look cool and if wrong, at least old! Lee