I purchased a set of boards form Steve WA1QIX to build my own transmitter but I went a different direction with the modulator.
I populated the PWM modulator and overload/shutdown boards and put them in a "chassis" made of FR4 with a power supply transformer, power switch, IEC power connector, and XLR. I'll include all of that with the sale. I did test the PWM section and it does work. The PWM driver board is unassembled, but complete with all parts except the fets and diodes.
For schematics see classeradio.com

I am asking $120 shipped OBO.
Please send me an email at *mycall*@arrl.net
73's!