Antoine, if you install a Electrolux AP Series motor, that would be a good option. If you do this, make sure you order a new set of carbon brushes for the motor & install them prior to installing the motor in your 86. However, if I had to choose between investing in a used AP series motor & a new Ametek motor, I would choose the Ametek motor. Why? Because the AP series motor could be anywhere between 31 & 41 years old. Just better not to take a chance on a motor that could be near the end of it's life.
If you do decide to consult a local shop & have a Ametek motor installed, a word of advice: Make sure the new motor draws less than 8 amps of power. This is CRUCIAL & very important! Our local vac shop, years ago, told me a horror story of how he installed a Domel 12 amp motor in a 89, & he wound up frying the customer's wiring & switch. Unfortunately, 8 amps is all the 80 series canister's power switch can handle. Also, if the shop can order the motor mount separately, ask them to install a Filter Queen single speed motor used in the Canadian Model 700....it only draws 6 amps of power & pulls 80" waterlift, same waterlift your 86 motor produces right now. If you want something with more power, a Ametek 116311 7.5 amp TriStar single speed motor can also work too....I have used it in the past with great results....and it pulls 90" waterlift, so about the same a new Aerus canister today produces.
Good luck repairing your Electrolux 86....
Rob