I bought a set from Clymer about three years ago. They didn't stock them at the time, but waited for orders before making the sets. The gauges were pretty spendy - $90 a set (go-nogo), plus there was a wait for the production run.
I have seen a home made set made by a friend. He made them like this:
Two new unfired steel shell cases - miked to insure uniformity.
Fill both with epoxy to stabilize them and help prevent "resizing" from the pressure of chambering. I think he used a slurry of epoxy and steel filings to fill them.
Glue a disk cut from a feeler gauge set to the case head of one to create the "nogo" . I forget the specs on 5.45 for what thickness of gauge makes the correct setback for no-go, but maybe can find it.
They seemed to work fine and gave similar results when compared side by side with my clymers. They probably are not nearly as dimensionally stabile as solid steel manufactured sets. I wouldn't let them be slammed into the chamber repeatedly and expect them to maintain dimensions. They seemed to be suitable for a few builds if treated with care.
I don't guarantee or recommend this, just reporting what I saw work.
s & p