Is this frame salvageable?

If you are in the Pittsburgh area, you could visit a shop I know that would give you a real answer. Personally, I think people on here are wildly over the top with this rust thing. You can stop rust from spreading, but you need to address it and keep up on it. Some around here use used motor oil and some use Fluid Film. Both are great for stopping rust. The nice thing about either of them they sink in and stop it. We are all guessing on here as we aren't there with you and really looking at it. Let me know if you are in Pittsburgh. I would patch it up and Fluid Film it like crazy. Mine is so coated it can't spread really. My frame is in great shape, but it is super low miles.

This is what a frame in the NE should look like at all times. No issues then.

Here in Michigan that's fairly common depending on the over all shape of the rest of the jeep and how much you want to invest and the type of use your son plans to do with it (dd, offroad,etc. )will all play a part in the direction you may want to go. I've repaired a few as bad fairly cheap. But I had the materials and the abilty to do it myself. The Safety caps are a good way to go but a little pricey. I've made patterns and cut out the rust boxed the frames with 1/4" plate, ran 2x3", x 1/4 angle from the front control arms to the rear control arms with flange nuts welded on for the skid plate. Then coated it inside and out. If you can't weld your self but did all the prep work then take it to a local guy you should be able to save it for around $500. But just remember it will never have a good resale but for a first car it should be fine. There TJs all over around here with welded frames but their only worth about $2500 to $4000 but their still a fun toy.

I’m doing a body off frame repair. It was a borderline decision to either repair or replace the frame. I’m comfortable with the decision to repair as I hit strong metal on the frame in the critical areas. I probably erred on the side of overkill. I took the body off, had the frame sandblasted, cut out any evidence of rust, treated the entire frame with several coats of Permatex rust spray, then installed Safe T Caps from axle to axle. Removing the body was important as it allows access to weld the pieces in properly. I’m also taking advantage of the accessibility to everything and replacing bushings, motor mounts, clutch, and several other wear items. Yours will be a great father-son project. Go for it.