I suspect that's stamping.
Kinda what I was thinking.
Although the pattern seems to wander a bit, which probably wouldn't happen with a die pressed into the wood. I guess a sloppy laser cut, but it is pretty sorry looking.
I've re-cut checkering, but not sure if I could do much with that.
'50's Pre-64 checkering wasn't too good, but there was enough pattern to re-cut. Not sure about those.
DF