This Jensen P10R wears the C5636-6 factory order code. OEM means "Original Equipment Manufacturer." This means they left the fender factory in an amp. This is for a Fender Tweed Super, Bassman, Vibrolux, Concert or Bandmaster in their respective configurations.

It has some other codes on it, but not a discernable date code. I believe it to be from late 50's or early 60's.

This is 8 ohms nominal impedance each.  

It may be a recone. I honestly don't know. It sounds very strong and healthy and does what it is supposed to do.

Please let me know if you have any questions.

Thanks