I picked up an ARC-5 transmitter at Deerfield and just finished converting it for 75 meter AM work. There isn't much original left except the chassis and variable capacitors. I even removed the tube sockets and put in a pair of 6L6's for the finals. a 6L6 is also used for the VFO.
I'm still finishing the power supply/modulator so I have yet to fire it up, but is should work!