How rare are 273 Commando factory pistons .030 over ?

I did not read the complete thread.
The original 273 pistons (both std, and Hi-po) were cast, and only available in Std, .005, .020 and .040 over size, not .030

The 2 bbl pistons were the same for all cyls. The 4 bbl pistons were different between the odd number cyls, and the even number cyls
"Back in the day", TRW had forged replacement pistons available in several over sizes, including .030.
If needed, I can supply the OEM part numbers, and possibly the TRW part numbers