Actually Scott, 30thtbird (Kenny) has pretty much decoded the Murray bikes of the 1960s and 1970s and has found that there are codes that will tell where a bike was sold and in some cases...even the options it had. I know that this is an AMF and not a Murray, but maybe the same codes would apply or similar. We all know that 502 on almost any bike means it was sold at Sears, so?
Anyway, post your serial number and maybe we can find out more. Also, I am working on trying to decode serial numbers for AMF bikes and I think the cranks have dates stamped on them, so if you can, could you pull the crank shaft out and check the numbers (if there are any) and post them here. I have yet find ANYBODY helpful or willing to offer ANY help to ANY of this.