What a great quilt, Gary!
On some of my vintage machines, I have to turn the handwheel to get it started, too.
I just sent the motor from my favorite quilting machine (1947 Singer 15-91) off to Jenny at sew-classic.com to get cleaned and re-wired and now, I don't have to "kick-start" that machine any more. :) I'm going to send her the motors for my slants after all the holiday crazy stuff settles down.
In these old machines, connections come loose, oil and lint accumulate, brushes wear down, wiring breaks inside the cord or motor where you can't see the breaks - maybe dozens of other things can go just a little bit wrong.
Do you know if the repair shop cleaned the motor on your FW and checked the brushes? For some shops, "servicing," means that they'll just clean out the easily reachable spots, check the timing, replace the belt and needle, wipe off old grease and oil/lube everything.
Modern repro motors are super cheap - it would be worth it to put one on and see how the machine runs. I bought one for a gorgeous 15-90 that was in near perfect condition and now it sews like a champ. Maybe give that a try?