Yeah, something like that, I'm guessing. I don't know much about Herc's, but I'm guessing the situation there is similar to the situation at Norman, a company with a similar history. From what I've been able to figure out about Norman bikes, only a relatively small proportion of the bikes made actually got the characteristic chain ring, and those are the ordinary 3-sp ones from the early 50's. All the earlier and later bikes that I've seen (only in photos) had plain chain rings. Even when the characteristic Norman cranks were available, bikes at the higher end of the product line came with plain (but higher quality) cranks.
I think that's a fairly accurate statement about the cranks. I have a mid quality Hercules club bike from the early 50's with the somewhat rare 3 speed Herailleur and Synchro shifter which first appeared in 1949. It has the plain and unadorned chainring. I also once owned a plain jane 3 speed sporting the fancy crankset.