Kohler Head Question (edit: pic added)

[4xbill 2]

I am working on a K301. After media blasting the head, I noticed a "2" stamped on one of the outside fins. It does not look like a factory stamp. It's kinda crooked and not an even indent. Is this something a shop does after machining the head?

[tec2484 1]

.002 under??? I have never noticed any thing like that before.

[RedbarnRick 5]

It looks like a second 2 is above and to the right of the first maybe 22 cu. in.that's about a 10 hp, it looks like the numbers were rusted away and after blasting that's what's left. just guessing