That WT May invoice caught my attention as I just tossed about 10 years worth of those invoices from my Dad's business.
It seems your dad and my dad worked about 1.5 blocks from each other at that time. We owned Strauss-Stallings Jewelers at 242 E. Capitol St and bought lots of office equipment & supplies from WT May, including a 4 function nixie tube calculator for a more reasonable $300-ish. He died in December 2013 and I've been going through decades of old business records for the past 2 years, shredding or tossing as appropriate. We'd probably still have that calculator (and a lot more stuff to go through) if the building hadn't burned in 1983.
