I successfully transplanted a xenar lens(excellent condition)from a doa rolleicord I got on ........ to my mint rolleicord that had a less than perfect triotar. Just got back from Alaska and the negatives look fabulous!
Is the focus register right ? I had a Rolleicord II with a Triotar it was an interesting lens, but the Xenar will be much better, but I took some excellent transparencies with the Triotar, I think on E4 film
I took a piece of ground glass and put it on the image plane then checked the focus with a 7X loupe then made a slight adjustment to the viewing lens. Near as I can tell from my negatives its great and the image quality I find to be more to my liking i.e. its more in line with my rolleiflex 3.5T.