Like you mention, the old Records can be stuck or very slow from regular reasons; packed up lint, in need of oil and cleaning, thread stuck some where,... You know it well. From looking down the top, I can only detect one plastic gear on mine, the part that turns the cam stack. I think there are some differences to these models, some swear they can detect two or three plastic gears in all.
To open the top of the machine, it's hinged in the back, and it lifts up in front (there might be slight variations to this, but I have only come across the hinged top lid). The top of the freearm comes off with a release push-in part, I think it's to the upper left behind the bobbin cover.
At the right price it's worth fixing up this model.
Last edited by Mickey2; 12-01-2019 at 04:04 AM.