14 x 7 Steel wheels

[R68GTO]

A guy I know has (3) 14 x 7 steel wheels 5 x 4 3/4 bp with the following stamps:
K18 8 XI
Based on what I've seen this decodes to Kelsey Hayes Romulus Plant August of 1968?

I can't find any info on an XI code steel wheel so I'm wondering if these are XT wheels where the top of the "T" didn't stamp strong? Guy said he got them (loose) with an LS-6 Chevelle he bought years ago. Two of the wheels have Daytona Yellow paint on them and the other has Ralley Green paint. He got 4 with the car but can't find that 4th one at the moment. Thinking about buying them but would like some input from this Community.

Anyone know of an XI code steelie? Opinions/thoughts?