Also at the very high end is Canepa Design -
http://www.canepa.com/ - we visited them in Scotts Valley during the End of Summer Cruise. Very high end mostly (all?) original stuff. They speciallize in Porsches (like being the national leader in 959 DOT convervsions), however they had 2 Cobras in the shop during our visit: 32xx Roadster (valued @ $1.2M) and a 4xxx full polished.
Good luck,
Randy R...