I can't answer all questions although I do have a NIB Turbo Mid Special in the UK but can't check it easily from here.
As for the Mid Custom, I have a NIB and a built one - my NIB has an alloy chassis and my built example has fibreglass so I guess it was changed at some point in the production run?
I don't believe the Custom Special came with roll bars as std in the kit but have been proven wrong before
Dan