I presume a speed shop might have a display like this? maybe it went out of business and someone picked it up, then passed away, now the kids are selling what is left? Just a spitball guess here.
Seems odd, but IIRC there were good and bad con rods for Chevy small blocks. 2 different lengths (400's and everything else?), but with different treatments. Presumably SBF's had similar things going on. Want to do a garage rebuild, but want a better set of rods? Go pick out what you want from the wall at the local speed shop.