We know it is no earlier than 1983 because that is the model year that Reynolds 501 made its debut. It is also no later than 1987, because the Falcon graphics had changed by 1988. The only two Reynolds 501 bicycles that I'm aware of were Shimano 105 and Sante equipped. My guess is that the frame was stripped of it's original components, with the possible exception of what appears to be a Stronglight crankset, which was found on other models of this level and era. This suggests the bicycle was originally European equipped and non-SIS, and would knock the date back another year, possibly two. Is there a model number on the crankset? What is the serial number?