dear Bob, thanks for the trust in my knowledge but you scared me by confirming the barrel is indeed set up higher! I regrouped, mostly . Setting the barrel of center ain't such a miracle. Take a lathe with 4 individualy operated claws and adjust it with the needed excentricity. Plug the barrel at one side and dril a centerhole. Move the barrel out to fully needed length and do the job. It's more or less this way based on a shrouded barrel like the 460 and dan wesson models, but then......
The firing pin needs to be raised too ....... no trick for that. yet.
I looked at some pic's of the new 929 with focus to the forcing cone and it looks like the barrel is indeed off center with the bulge in the frame.
Think I am not going to decide what to do at this moment. In a couple of months there should be some 929's at the local gun store to hold and look at.
I am very curious how the firing pin issue is fixed in your case.

After the technical challenges I'll check with the local ipsc guys to be sure all the effort is not in vain.

best regards

HP