'85 was the last year for the jumpseats, mine has them factory.
'86 and up didn't have the jumpseat option.
Also Brats only had the centerlamp in '82, the first year of the second generation Brat.
I need to tackle the rust in the rear wheelwells like you are doing, I can see some rust eating through the paint on mine.
my brat has the factory plate on it saying its a 85 but its titled as a 86 so no factory rear seats where a option for it:(
and the first year of the 2nd generation brat was 81 and they came with the lamps in 81-82
yah these have bad places to rust, its from the bad design it makes dirt/stuff get stuck up in there which almost never dries out hear in the northwest causeing the wheel wells to rust out, i hope yours turn out good when you do it i just started today welding the drivers side back in and its tricky getting it to fit good im finding cutting the top of it in couple places helps and so does a vice to shape the curves and especialy a hammer:D