ZL-1 stamping numbers

[COPO]

Just went down in the basement, front pad is stamped TO307ML, down near the oil filter is stamped 19N620923, which is the VIN for car #51. (block came frome original owner of car #51) Caps are stamped 356, Raised casting date looks like 1 1969 then 472 under it. I have read that the 472 is an inventory number and it is directly below the casting date. These numbers are cast upside down on the passenger side of the block near the front of the engine. I'll look a bit more this weekend when I have more time to see if these ar additional markings.