I am trying to install a simple trim kit on what I think is an American Standard faucet. I can’t figure out how to get the old trim off. The knob came off as planned, but the portion of the valve the knob screwed into is what I am having problems with. I don’t think there are any set screws holding it on. I’m tempted to pry it off, but if I break something I will have to replace the whole valve and I do t want to do that.

If there's a screw it's gonna be on the bottom, but it's been too many years.

Maybe one of those compression fittings, but you would think it should go on and come off easily since it’s a trim piece

Unique decor

try unscrewing it.

a lot of the older ones screwed on so they could be adjusted to wall thickness.

At this point, I might just cut the pipes and install a new faucet. I so dang frustrated with this. To top it off, the kitten went down the hole in the wall and got under the tub. Had to pull her out by her hind legs.

I can try, but if I break it, here we are at 5:00 on a Saturday night.

YouTube might be of help although I couldn't locate one exactly like the one you've pictured that utilizes trash bags and duct tape.

All of the you tube videos I saw had newer, cartridge style faucets.

I am still trying to fix the hole in the wall so the trash bags let’s those nasty children in the house still use the shower in there.

I think that piece just slips over the valve stem and is held in place by the screw that holds the handle on.
If so, it would turn when the handle is turned, and it should slip straight off.
Might try wiggling it while pulling on it.

I kind of think you are right, but I’m not sure. I might give that a try.

Always an option. Except while on a zoom call.

Unscrew the sleeve and put the cartridge in this probably four screws

Screw it, I’m going to put in a new valve. Might as well, the wall is open. Then my trim kit options are better. I hate plumbing.

That the put in a delta valve lifetime warranty