Prolly just gaps in the set. Or - very common - he is indeed missing the 'most used' so often taken away to be used as standards to check other metrology. And perhaps missing the 'wear' blocks?
Those are basically what I had to backfill.
I had also added a set of 'mediums' as well as clamping kit for long stacks, just also added a set of the LONG blocks, can 'theoretically' get up to over 90 inches now.
BFD.
Longest granite plate here is only four feet. But... at least I can 'qualify' a mic or caliper or bespoke gage as well as I'll ever need that, so.. done with acquiring any more such 'treasures'.
Well.. maybe a decent Cadillac Gage Pla-Chek?
Old men. Old Iron. Old habits.