Hi Philip,
Gosh, i'm sorry it's taken so long to respond. I WAS able to get the 997 wheel to fit with an adapter. I didn't complete the fitment only because it proved to be to expensive to get the steering wheel controls to work. You are welcome to the adapter if you want to continue with the project.

Hello. Fellow Oregonian and 996TT owner here. I saw your post last year about retrofitting a 997.2 steering wheel on a 996. Were you able to get it to work?

Thanks,

Phil