Who makes a full carbon frame that takes a 27.2 post, an IS2 style headset and has downtube shifter mounts? I'd be looking for something with a raw carbon finish too.

good luck finding the downtube shifter mounts- I havent been able to find them- maybe a custom?

Trek is the only recent one I can think of that has used DT mounts. To get all that you are looking for it's probably an old Peugeot/TVT/Look from the late 80's and none of them were full carbon.

I don't know of anything new, but a classic carbon frame would be the Kestrel 200 EMS which came in naked carbon and downtube shifter mounts.