We're guessing that it is late 60's or early 70's. We found some forum posts online that told us where the date codes would be, but all that is left is some goop where the stickers once were.
It does seem to be really well cared for, though. The wall cord could stand to be replaced, but aside from that and the missing needle, seems to work. You can produce sound if you turn it on and run your finger along where the needle should be.