Someone know's where to find the serial number on these gun's. I've got one in 32 ACP in pretty near new shape. Has one extra clip and factory box. Just no idea where the serial # is.
Assuming you are not just over looking the serial, I've seen later ones with the serial ground off, for what ever reason. With the serial on a small flat surface on the frontend of the frame it is easy to remove. With good photos we can give you a serial range that it was made in. There were a lot of changes over the years.
Also, the box might have a serial penciled on the outside somewhere.