[First, I wish I could have simply edited the earlier post(s) to add info, instead of creating new posts]
Well, it's wired - I chopped off the old wires as close to the old motor as humanly possible, and installed the crimp connectors; then I plugged the new motor's connectors to those (difficult fit!). This leaves about 8" more wire back there but I'd rather not cut/solder until I know everything else is OK.
Fire extinguisher at the ready, I plugged in the stove and the fan ran for a moment (I noticed that when disconnecting power to the stove and then plugging it back in, it always runs for a couple of seconds even if not turned "on"); very quiet, I think.
Then I attached the motor to the stove and, as anticipated, access to 2 of the 3 bolts is crazy! I sincerely hope they are tight enough. Then, plugged it back in again and, again, runs but quiet.
Next, time for the fan blades. This is odd, the 1/8" Allen wrench would not fit the replacement 502221 blades, although a 3mm one did fit. Also, the central boss is bigger. I made a decision, reversible at this point, to re-use the old fan, it cleans up nice and I'll remember which wrench to use. Yes, I added anti-seize compound. For a third time, plugged it in, maybe a wee bit louder but nothing like the old one.
HERE'S THE QUESTION: Hmm, is there a specific instruction on mounting depth, as in how far to slide the fan blades onto the motor shaft? I took a look before disassembly, it looked like the shaft stuck out past the fan's central boss perhaps 1"16 to 1/8", that's where it is now. Is there and ideal value to (A) not hit anything, (B) maximize flow?