Christiaan Phleger
Member
Yeah I would have to surmise that there were other film developers in the mix from a myriad of labs either small and independent that would service the "drugstore" photo counter. Recall that in that era many "drugstore' had small labs on site or enough stores could support a small lab nearby with photo needs and those labs would and could use whatever premixed or formula they chose. What those lab chose could be D-23, DK-50 or an Edwal, Ethol, Defender or Agfa formula. HC-110 was more of a 1970's era and took more favor with speed/consistency usage in news/editorial, and remember there were cheaper options it was a premium Kodak product and priced accordingly.. I would not instantly assume D-76 even in that era.