I doubt you'll find exact dates, but if you check all your '37 books they'll be copyrighted in '36 ... usually way back, production for a model year started late summer the previous calender year and sales started in fall/winter, like Sept - Nov ... also most jurisdictions back then titled the vehicles by year of first sale rather than makers model year, so it's common to find, say, '37's originally titled as 36's .... production of a model year ceased sometime in the summer of that calender year for the changeover to the following years model
Bill