rafflesdials.com
I don't know about a rep Tudor DD, but you could check the TDs- Trusty has a decent selection of reps, I'd start there.
Building one wouldn't be that hard- Rafflesdials has most of the parts you need and you could either get a clone eta 2834-2 or splurge and get the swiss 2834-2. I would think that you could build one for $200-300, maybe a little more if you go for the Swiss eta.