AAron,
Your keeping to originality retaining the TRX wheels reminds me of the many 635's and 400i Ferraris that had the 390 and 415 wheels. Don't remember the process but there is enough meat to remachine the wheels to make use of 'normal' tires. Never did it but had heard of it. Just a thought if you have an extra/curbed wheel laying around to experiment with.

TobiasMB
300SE, 300CE, C280Sport, 190/5.0