Yes. They are 48IDA 4's, which are the last iteration of the IDA. The only difference with the "4's" v "1's" is the "auxiliary venturi". (I've never seen 2's and 3's). That's the changeable choke in them. The first two IDA's were listed as being for the GT40 and were built/assembled with 42mm "chokes". The "4's" were built with 37mm chokes.
The 1J is the date they were made. October 1971.
It's mostly the "Cobra" guys that are looking for '60s dated carbs. Until maybe 20 years ago, no one cared. The only differences are the dates since they are all of a modular construction.
The biggest user of them at that point were VW's mostly in Dune Buggies.
They are all made in Italy up to somewhere in the '80's or '90s when they were made in Spain, then somewhere in this century had the country completely blank.
The only real difference is that the top and bottom were originally held together with a stud and nut on top. The Spanish ones replaced that with just a bolt. The other differences are just the size of the choke they came with and the calibration, i.e., fuel jet, air jet, emulsioln tube, idle holder and idle fuel jet, which are all almost infinitely changeable.
The unique component to your setup is the intake manifold which is unique to the Pantera racing program in Europe where multiple carburetion was legal in the factory classes.
Speculation on production numbers of that manifold are probably 100. Where the rest of them are, no one knows. Only a few have ever shown up for sale.
Carb copies are now being made in China with no indication of where they were made. Some are being bored out to 51mm mostly to use on rotary Mazdas now.