Hi Darryl,
Thanks for that. well that then confirms that mine did have the toolbox attached at some stage as those 1 inch band marks around the handle bar suggests that something was attached for quite a number of years and then removed. I definitely think you are correct in saying that it was optional as my electric unit is totally original and they are absolutely no witness marks at all of anything being attached at any stage of its life.
With this model listing it seems almost certain that mine is a 170413 unit. It's amazing of how many configurations that SB made of the Supercut which now makes sense why each one you see is slightly different to another. I guess as they were made for industrial applications there would be so many differing requirements from contractors etc. that they had to make so many variants.
BTW my electric 20 inch is a 170114 model.
Gee I'm loving this old heritage stuff you're digging up. It just adds to the history side of things so much.
BTW I'm involved with a History Committee at an SANFL Football club and thus you can probably understand where I'm coming from.
Keep it coming Darryl.
Cheers,
BB.