You can buy a replacement remote at most any store with an electronics department. Many of them will work with your TV, but you may lose some of the "OEM features" with the lower cost remotes.
The "Pummel Drive TV" brand was originally sold by Midwest Supply in Elkhart. Their website is:
https://mwss-inc.com/ and they also have a "facebook presence" at:
https://www.facebook.com/MWSSinc/pos...1415727472114/ But that link apparently changes from time to time, because currently it goes to another "Midwest Supply webpage" not to the "Pummel Drive TV" webpage. That could mean that they no longer have any in stock (a common issue with RV supply companies) or that they just needed an updated link.
Contact them, they might be able to direct you to a source for a replacement remote.
Unfortunately, far too many RV supply parts are a "one and done" shipment, often from suppliers in China with an excess inventory, sold to the highest bidder on AliBaba or some other "sellers website" to the highest bidder, bought by someone in Elkhart, sold to the RV manufacturers for "pennies on the dollar" and when sold, never purchased again, so no parts inventory was ever bought or even planned.
For the most part, RV TV's are a "one and done" and if they break during warranty, they're almost always replaced with a locally purchased component and if they break after warranty, Keystone doens't care what you do with "YOUR PROBLEM".....
RV fireplaces are another "don't try to repair it, just replace it" feature.....