It appears that there isn't one. So I'm going to share what I did in case it helps anyone else.
1. I ended up buying a Danco Trim Kit for a Delco Shower because it uses a similar handle movement.
2. I took the adapter that they provided for their handle and drilled it out and shaped the opening so that it tightly fit the end of the American Standard valve. That allows the new contemporary handle to attach to this older valve.
3. The trim kit has small circular screw plates included but neither of them align with the American Standard valve body. So I took the old trim, measured out the openings and their relationship, then I 3d modeled and printed a replacement part that would fit my shower valve. I test fit it and it worked. So I lightly sanded it and painted it to match the rest of the trim kit.
4. When I installed it I found that the american standard valve body shroud interferes with the new handle keeping it from completely opening the valve. So, I removed it and put it all together and it worked...but I could see past the handle and into the valve body and was concerned about water getting back in there when the handle was tilted into the on position.
5. I 3d modeled and printed a new part that is essentially a cup that slides over the valve body and snaps into the original screw ring that I had printed. I added a flexible gasketing in the back of the cup to help seal around the valve body and the cup directs any water that gets back there back out and through the trim.
(I should have sanded it a little more because a lot of the printing artifacts are still visible when you look closely)
Tested it and it works!