Jets are usually stamped on their sides which the way the Ford mounts them on the bottom of the bowl they can’t be seen.
The jets are test flowed and marked for flow against a standard which is actually pretty close to their drill size in inches. With a small drill set you can get pretty close by inserting the smooth side of some bits till you get to the go, no-go condition.
I presume this is the import version of the 2100. I’d expect that the 1.23 inch bore version is probably going to have around a .068 jet plus or minus a few thou. Like I suggested taking the round end of some small drill bits. I’d expect something in the range of 51 to 48 which would be dimensionally .067 to .076 inch.