Thanks very much for the suggestions.
I'm going to pass your post on to my mechanic. He did scope the interior of the turbo and it is clean. I know when my 911 has been sitting for a while, there's always a bit of blue smoke from the turbo when I start it, indicating oil, however it clears quickly.
I'll let you guys know what we find. Perhaps it will help someone else. I love my Conquest but it's getting harder and harder to find parts for it!