holley metering block ?s

They have # 50332 on both blocks.
Both blocks also have # 400634 142
Other than these #s they are marked PRI & SEC on top.

I also got a second pair marked # 50332 on both blocks also.
They have #s 4006371 146 on both blocks.
PRI & SEC on top same as first set.

My best guess is the holley block # is the 50332.
The other #s may determine the combination of drilled threaded inserts
installed in the blocks for whatever their intended use may be. These inserts are the
only difference between the blocks I can see. I am not sure if these inserts
are holley installed or some aftermarket carb builder like braswell?
Of course this is a guess. The #s do appear to be stamped before the coating
was put on. And all #s have the same font. So they may be blocks someone
removed from a modern holley HP type carb.
I figured it was a long shot hut was hoping someone may have seen blocks like
this before to give a clue as to what they are from.
All of my older holley blocks don't come with the screw in inserts as these have
so they are unfamiliar to me.