I'm new here but have been around Gibsons since I got my first one about '72.
As I recall, the J-40 was brought out in the early '70s, a square shoulder dreadnaught. It might have the "double-X" bracing Gibson introduced a bit before that. Kind of like a lot of guitars they did in the early '70s: J-45 Deluxe and similar. Not bad guitars at all, really, and some sounded pretty good in spite of the heavy bracing. I owned a early '70s J-45 Deluxe that sounded darned good, actually. But it needed a neck set (read on).
I thought the J-40 was a mahogany backed guitar but have read references to it as walnut. Also thought it had a standard pinned bridge, but have heard "pinless". Regardless, if what you mean by "terrible" action is "high", there are things that can be done, and mostly likely a neck reset. You may or may not want to do that. Any problem is fixable, given enough intent, skill and/or $.
As a reference, the book "Gibson's Fabulous Flattops" talks about this model, maybe you can get a copy or find it in the library. Or call a dealer like Elderly, etc. and ask for the repair shop and describe your guitar and discuss the issue. A lot of knowledge in the bigger vintage shops.
You can also find info on-line and do a serial number search to narrow down, a bit, just when it was made.
Glad you've got yer mom's guitar!
|