Interesting info ! Also seems to be a difference in VIN stamp locations, fonts, etc. So number 10 and 34 blocks for sure had VIN by oil filter. I have a pic somewhere that I took of block from #17 ( if I recall correctly). It was individually stamped digits on the front deck.

Was there any rhyme or reason or patterns on the VIN stamping?

A few were VIN stamped on the pad. Most seem to be stamped on the side of the block.

Here's another.

It's the original engine from ZL-1 #52, last of the Gibb cars. The engine is in ZL-1 #33, both sold new to Bob Jane in Australia. #33 was road raced there since new and is restored to original racing trim. #52 saw some drag racing usage, ended up as a daily driver. Said to have been destroyed in a crash.

Any updates?

No.