Hi Ken and Mod CJ,
The thing that gives it away as being an early version is that the ID plate is marked as SC and then the later machines were denoted as 17 due to it being a Model 17.
If you look at all the early model 45's built around 1968 ~ 1970 you'll see that their ID plates were marked as 45 XXXXX the same way as the Supercut of the same era was marked 17 XXXXX opposed to early production SC XXXXX.
Cheers,
BB.