can anyone tell me what year (roughly) the red band on a mercury thunderbolt 50 hp is.i'm looking at buying one with a parts motor but the parts motor has a blue band on it. i'm wandering if the parts are even interchangeable. especialy the lower units... i can't get the serial # from him because the motors are 2 hrs away...it's running but needs lower unit work.if the blue band unit will fit on the red band engine,than it's a good deal at $250.....any imput would be helpful.thanks