Lol! Those old erasers from the days of "keep your pencils sharp." These all appear to be made by the same person. Either personal desk ornaments or possibly made as a coworker Xmas gift (Yankee swap, etc), 1st, 2nd, 3rd prize trophies ... something that only the coworkers could appreciate. We used to blow off steam in the lab making dumb shit from whatever was laying around. Back in the mid '80s we had <young> engineers running around acting foolish wearing "floppy hats" made from ripped open 9" (?) Floppies (magnetic disk in an envelope, standard for PC data storage at the time) to making clocks out of old multisite probe cards. Pranks and foolishness were great stress breakers.