I dont remember delta making a spout like that. I cant see the end of the stem where the handle fits on very well. Take a close up of the stem and the underside of the handle where the stem fits. May as well throw in a side view of the spout.
I'm kinda thinking its a Delta knock off.
The handles,stems,seats&springs will interchange but nothing else will interchange between a 1991 Delta roman tub valve and current Delta roman tub trim.