And usually it was a BSR changer in them. Occasionally on high end models you would see a VM changer fitted. Getting the idler rebuilt, proper cleaning and lubrication where needed should get you a working changer. No belts found on one of these.
As Matt said, those Idler wheels are the culprit. Turntables found in older Magnavox turntables had dual wheels, the second being for the change cycle. The newer ones had a single idler wheel as shown in the second pic when you scroll down. That wheel presses against the inside of the underside of the turntable and must have firm contact. --BB