I went through all the catalogs on my CD and 73-75 were all blue stripes with white overlays. 76 and 77 both had green colored overlays with the blue stripe. So without question your bow having the white overlays, it is a 73, 74 or 75. No good way of nailing it down any better than that as far as I know. The serial numbers arent much help as they started over or didnt have much reason to them that I can determine. I have a buddy that worked in the bowroom at Bear Archery in 1975 and will ask him tomorrow how they determined the serial numbers.
Great bow you have there anyway, and its a good representative of the bows built in 75.