029-1 block stamp decode help

[Ladysmith Bob]

New member needs help to unravel unusual pad stamping. Casting date is 2/8/63

 

[PurpleBeeper]

It "looks" like maybe someone added their own stamps....maybe a rebuilder's mark?

 

[RT K_line]

I have seen that cross on one of my blocks many years ago and looked into it. but I can't remember if it was oversize lifter bore or undersize bearings somewhere. Sorry that's not much help.