As per my email offline, thanks for this Tim!
I would like to find out how many 1941 Master Deluxe 5 passenger coupes were built across all plants, as if there is a total then perhaps I can work backwards to know how many were produced at Regina. Mine is body 112, and based on the beginning and ending serial numbers it was built in March 1941, very, very close to "the end". I don't know if body 112 is tied to it being a master deluxe, or if all the coupes (5 passnger, business coupe, special and master deluxe) were all in the same number series. Regardless, its one of the very last coupes built there, I'd like to try to figure out how close to the last!
I don't know if anyone on here has this info. Mr. Hayward probably did, as he seems to be the leading expert here on many forums and websites, I hope the information has passed on in the detail he had it.