They didn't start putting numbers on frames until 1970. Find some Harley literature (Bruce Palmer book?) that says that a 48 panhead never had frames numbers on it and take it to the dmv and show them. Don't let them make you register it as a special construction. It will decrease the value. There are some articles in you google it that say frame numbers started in 70.
They did pu id numbers on pan frames it will be on the left side under the seatpost where the downtube meets the seat post it will up side down
NO, no number on frame vin number is on left crankcase.
Panheads had no frame number,frame numbers came in end of the 60's begining 70's