Back in the 1970's when my hemi came out of the 71 GTX to go to the machine shop, i stamped my name into the ID pad on the block, for theft deterrent purposes.
The original; engine to the car.
So as far as i know, Jim Valuckas most likely is still on the pad, unless the owner had everything milled off.
Anybody could have stamped ID pads with whatever they wanted to.
Wasn't a big deal back in the day, like it would be now a days.