I think the very first Boeing 737's were later called the -100 (only after the 200 came about).
I saw one in Continental colors at KDCA and when they went in reverse, the plane ligtened on the gear/oleo struts.
I also think the later 200's canted/angled the thrust reversers to avoid the strike.
The DC9 I flew could easily deploy thrust reversers while nose up (or illegally inflight) but it was always encouraged to have the nosewheel firmly on the ground.