Yes--the jet block stamping matches stampings on the carb body in each case.
This is something I didn’t know. I was considering having a jet block made to match the one I already have.
It’s just a shame that Burlen have no interest in doing anything for the GP2 carbs. Gp3 a fitted to the Goldstar yes but not anything smaller.
I’ve never made a jet block, but I do have some TT’s that have mismatched blocks that need boring. I stand to be corrected, but this is my take on the situation.
Unless there is something peculiar about GP2 that is different from the TT carbs, then you could get one made. The jet block would be a little finicky to make, but nothing there that would be that difficult. I suspect the jet blocks were a select fit to the carb body, because (based on the TTs) there seem to be slight differences in fit between carbs. Once they were fitted, then the jet block and carb body would have been bored as an assembly and marked according.
So you could copy an existing one, but turn it to fit your body. Leave the bore slightly undersize, assemble the two and then bore the venturi. Depending on the situation, it would likely be cheaper and easier to buy another body/ block assembly with matching numbers. Might cost less and be worth more when you are done. Another thing to keep in mind is what sort of life did the carburetor have. Running unfiltered, there may be enough wear in the body that even with a new slide, there is still enough slop to necessitate sleeving the body. There is a fellow a couple hours south of here that does that for just under $200 usd. ( sleeves the body and uses a stock slide)