Regarding your 700
The Model 700 is just plain jane! They originally come from the factory in a rather dull looking aluminum finish, most of us just polish them up to make them look a little nicer!
There was an add on for it called the "Dirt Searcher" basically replacing the top cap with a cap/light installed. Otherwise, as you see it, is how it came from the factory! I'll attach a video below. It is a 750 but basically the same machine. The 750 was just a 700 with the dirt searcher light attachment as standard.
As for the black bumper replacement, you can just have your local Vacuum Shop install one for you. Its nothing but a black strip of rubber riveted to the machine.
For the motor, did you run it without the belt on? The brushroll could be locked up (old grease or spun in bearings) and prevent the motor from turning.
One common mistake people do when they service these machines is that they forget to replace the sleeve spacer (metal hollow tube in between the bottom motor plate and the fan)
Doing this, basically locks the fan against the motor housing and prevents it from spinning.
If that's not the case just open up the top cover and (with the machine unplugged of course!!) see if you can spin the commutator by hand, if it doesn't budge then there lies your problem.
To double check, just remove the fan completely and try spinning the bottom shaft by hand, it doesn't move then its possibly a shot bearing or a bearing with old hardened grease within it.
BUT if it does spin free by hand and there isn't any up, down, side to side play in the shaft then it could possibly be that missing sleeve spacer I mentioned earlier.
Some pictures or a video would be great help in assisting you as well. Take a few shots as you tear it down if you can.
http://https//www.youtube.com/watch?v=Qd33P0L8VHw