The cord had no switch and the wiring was shoddy on the inside, so the cord was not original - can't use it to date it.
The strain relief was not correct, and can't be used to date it.
The cord exits very close to the base, which appears the same as early century types.
The base is 2 piece, so that makes it an early version.
No stickers under the cap.
If it's a 2 piece, it's the 1st version base. Late 60s to 70ish.
4th version. 1st version had no seam at the 'pinch' and a rotary switch on the side. 2nd version had some sort of overheating sensor. Neither has been seen yet. 3rd is 2-piece with a copper finish. 4th is 2-piece with brass finish.