you definitely should not have accepted without a better inspection but whether you deserve a refund I think depends on the descriptions of the machine you were initially given.

Person to person sales are done as is so unless he said things like no playfield wear or in perfect condition I think this one falls on you for lack of inspection, as shitty as it is that he's ghosting you now. (which makes me think he knew and was happy you never looked)

Minty mint is far from what you got though so I think you have recourse.

Sales like this are as-is, but putting minty mint in the description means something.

I would take it to small claims court if the guy keeps ghosting.

Sellers should be required to indicate which user bought the machine so that user can be authorized to leave feedback. I'm sure scammers like this would just game the system but they could be restricted from selling for constantly saying "someone off site bought it" when it's not true. It would be really easy for the OP to prove he bought the machine since he now has it in his possession and can take pics to prove it.

I know several other marketplaces that ask you who you sold it to when you mark the item as sold and they usually use who you've been messaging as the list of options.

Their lack of inspection was partly based on the description saying it was minty though. Do you think they would have inspected it closer if the ad had said there was playfield wear? The answer is undoubtedly yes.

As is sales still don't allow for deception by the seller, They have to be honest on the ad.

It would allow them to bring back negative feedback in a way that avoids the issue it originally caused so I think it's worth looking into.
Also makes it easier to catch if people are faking sales to push the market up.

Kijiji asks you after you sell an item who the buyer was and it gives you options based on who you have been messaging lately. Obviously the seller could choose not to answer or lie but if you have problem sellers who are constantly saying it was someone else not on this site who bought it you could probably figure out that they are lying pretty easily. The buyer could also indicate that they were the one who bought it with a chance for the seller to appeal. It shouldn't be that hard to prove who is lying if the buyer can produce pictures of the same machine that was sold.