Hi Richard,
I like the models you've built so far, very nice.
I'm playing with R/C too. At present I have something which can control a motor using PWM, but I've bought a cheap DCC decoder to try and interface with that too.
What sort of R/C hardware are you using? I'm using a little board based upon a TI CC2511 microcontroller. One of them plugged into a laptop to send the commands, and another on the loco to control the motor.
Regards,
David.