1 - did you check the tracks to be sure there were no obstructions e.g. coins,
fossilized french fries etc?

2 - the seats are super easy to remove, 4 bolts, roughly 12-13 mm and
perhaps you can function check w/o the seat being under load.

3 - yes, use SEARCH, because i'm quite certain i've seen tons of photos of
the seats / motor either here, MBWORLD or BENZWORLD in the 210 section.

__________________
-- raymond~
47º 34'N 122º 18'W