W&B info for PA-12 Super Cruiser

It looks like I'm probably going to be able to give instruction in a
PA-12 that recently went on-line at a nearby FBO. It sounds like more
fun that just working with private applicants.
Looking over the paper work, I can't find any CG range or loading
limitations for the aircraft. We have the POH (really more of an
owner's manual) and the A&P has done an excellent job of detailing all
the W&B changes, but I just don't have anything that tells me what the
valid envelop is. It doesn't appear anywhere in the owner's manual. I
know some older planes have loading limitations instead but I'm not
seeing that either. The other CFI didn't seem to haqve ever really
look at it.
Is this something we can get from the FAA somewhere? Is it possible
that the CAA didn't require a CG envelop back then?

-Robert, CFI (tailwheel and sea planes !!)