The folks at Fireplace Remote
The folks at Fireplace Remote Controls were great. They answered all of my question before and after I purchased 2 remotes (one for each of the 2 fireplaces in the house).
The technology has changed quite a bit since the original remotes and receivers were installed over 10 years ago. It takes considerable patience to successfully explain programming digital control units to a woefully analog customer, but they did it, and they did it well.