Yes, worn chisels are a possibility (as is repurposing broken chisels). a couple of the cast steel chisels in the seaton book are broken, but one has to account for the fact that they're also (or were) about a 20th of an inch thick at the bevel when made. There are separate firmers for heavier work, but they are by no means thick, either (some do have small bevels on them, though, contrary to claims I've seen that early chisels never had them - I don't know who ground the little bevels on them - it may have been a common user modification).Although you have to take into account that folks had many half worn chisels to use for other jobs where it might have been wanted.
I only brought a nice little Fuller chisel from the folks, not sure if it was originally short, but might come in handy someday.
I would have had one use for it paring in confined spaces, but just pulled the offending close tenons out instead.