Like Ron already posted, your replay is clean as a whistle!
Regarding your driving lines, there's not much to improve. The lines are there, except for a few spots:
-Try to end at the outter right part of the track coming out of the S curves. This grants you more speed through Dunlop curve, resulting in a gain of about 3 tenths up to Degner. As a bonus you'll get less oversteer there, since you increase the radius.
-Going into Spoon, try to brake earlier. Correct me if I'm wrong, but since you missed your braking point by a mile, I think you're systematically braking too late there. My brake marker is the non-grass part on the right side. I always brake just before that part. Then hit the apex on the inside with partial throttle applied and then continue the 2nd part of Spoon like in your current lap 👍
One other thing I'd like to suggest, is to longen your final gear ratio by about 0.200. The Vette loses power when you approach the red line, so a longer gear ratio might bring you some more.
For the rest respect for driving so smooth with a pad. With GT3 & 4 I was almost as fast with the pad as with the wheel, but I can't even come close with GT5P. Great performance
Edit: I had a 51.3 T1 in my run. If I remember correctly a high 51.1 is the fastest I've seen.
BTW, Maz, does my latest posted replay (RAR) work for you?