Edison Amberola 30 study?

[cyanblue]

I know, I know, the little common workhorse…

 

Have the Edison Amberola 30 variations over the full production run ever had a posted/published study, even an approximate serial number and date range for those variations?

 

For example, the very first Amberola 30 run with gold pinstripes, exposed speed control, front grill, etc. and when these early details were dropped.

 

And the opposite end, the late/final version with the more plain case, and the high serial range (I believe in the 220k range?).

 

Thanks,

Patrick

Toronto, Canada