Hey Bethe ...
To test the HC-110, dilute a few drops of it with several drops of water and put that on a film leader (guess I'd better say emulsion side for completeness for other readers, but
please don't take that personally
) in daylight/room light. It should start turning darker within a few minutes. If you don't dilute the syrup with water, it won't develop anything. HC-110 lasts a very long time, even in partially full bottles.
Verichrome went pancromatic in 1956, and was produced from 1931 until 1956, I don't know what times might be, but I'll see if I can find something for you. I'm sure others will chime in in the mean time. HC-110 was introduced about 10 years after Verichrome production stopped, so you'll have to work out some scheme for finding approximate development dilution and time.
Lee