Richard, Welcome to the Forum!
I've had the same trouble as you trying to find them (Quest). You'll probably have to go through a Montana Dealer, or you can call them direct -
Quest
514-457-2555 (Canada)
www.questhifi.com (Not Verified)
Keep in mind, the unit is worth about $49, so anything past 12 minutes of effort finding a remote and you'll be loosing money. Chances are high that it doesn't even work, as there have been many problems with these. I personally would just replace it with a better unit.