Tom, after checking the registry, and using all my powers of deduction, I would think that the frame # is likely 06104. The reason I say this is because an 08104 number would be a 1954 model, and you have a straight leg frame with an early style brake pedal.
Mike, you've been home a week and we haven't gotten an update on the registry? What have you been doing with all that free time? LOL!!