Great links, have been on Ben's site for years!
I was more looking for past experiences in endurance racing. The good, the bad and the ugly. GT40 or not, endurance racing is a huge challenge.
The technical regs for the Nurburgring 24hr suggest a vehicle's eligability comes down to the organisers. Also, a minimum vehicle height of 1100mm. The same regs are listed for the Dubai 24hr.
Perhaps a roof vent or 84mm high verticle fin would be required!
FIA's Appendix J - Regs for Sportscars suggests all would be fine, but ultimately it comes down to the interpretation of the event's regulations, and the descretion of the committee.
Apparently the Valencia 24hr has been cancelled this year - not sure for 2010, and the Brit-Car 24hr will be a 6hr for 2009, and back to 24hr for 2010. I suspect the minimum 1100mm rule for the UK race too.
Logistically, a nightmare from Australia, but I'm talking with guys who've done this before. Not something to be considered lightly, so any advice would be appreciated.