They were a Canadian company until they scampered south of the border.
Sounds like you have the RDR "Red Dot Ready" model, which was meant to mount a red dot. They also sold an LDR "Long Distance Ready" model with a Pic rail that was meant for scope mounting. Haven't seen any adapters to put a rail on an RDR, though, but in theory if anyone makes such a thing to adapt from the hole pattern of one of the red dot models Grey Birch supports you could still be in luck. I'd just stick with a red dot on an RDR.
