Removing Film from Mason Jars

Soak or scrub with acetone. Outside. If that doesn't remove it nothing will.

I'd try vinegar if you haven't already. But the denture cleaner, as one mentioned, seems like a possibility too.

You might try Barkeepers Friend, don't know if it'll work or not, but it's worth a try. Also, there is a product at the auto store to clean headlights - but it's probably made for plastic. Depending on the emotional value, it'd probably be cheaper to buy new jars.

If the film is on the inside, try denture cleaning tabs.

Or try soaking them in soapy water with a little ammonia. Leave the house while they soak. If they are etched, this will not help. By soapy water, I mean regular dish detergent, preferably Dawn. It gets out/off a lot of stuff other soaps won't.

I would try soaking them in a mixture of borax and hot water.

They probably have what is called "etching". It's usually caused by washing in the dishwasher - usually from soft water & too much detergent. This will not come off. So you either have to live with it or buy new jars. Sorry.