Thomas & wennjo - thanks much for all that info. Especially the BobLight link which shows that a 315MHZ receiver can be detuned! This was the only missing piece for me, and unfortunately for my wife, it will probably get me back to working with the Arduino again.
After the RF receiver, I'll see if a 315MHZ transmitter can be modified to replace the CM17A. I'll definitely check out your libs as a substitute for the current Playground set. (I know the stuff I wrote wasn't the best implementation.) I like that fact that it has a buffer too.
Phil, since the BobLight link that Thomas posted used the 2400bps receiver that has a tuning slug, I'd probably go with that rather than the crystal controlled 4800bps model - just my opinion.
Thanks a lot
John