Mark Hama did a terrific total overhaul of my Kalloflex (the Godzilla of TLRs) two years ago. Tore the shutter down to parts and sent me a jpg of it reduced to levers, gears and springs while he was in the middle of doing it. BTW, Mark Hanson will work on some Ricoh TLRs, but they are among the few Japanese TLRs he'll work on (strange, go figure). But from my experience, Karl Bryan is the man to work on Diacords and Ricohmatic 225s, even though he is better known for Autocords. He turned me on to the 225, whose praises he sings.