That happened because that's what the manufacturer did 22 years ago -as I explained in my previous post. Progressive is usually pretty good. Even if you have to send them pics of the MH, the serial number tag and the VIN they should be able to work it out. I would either work it out with Progressive or find another insurance company. But the insurance company telling you to go back to the DMV after you have tags and title is the tail wagging the dog. Who is the manufacturer? Call them, maybe they can provide the documentation you need. I know Winnie and some others are pretty good at historical information. If it's some brand that is no longer in business then that's a dead end.
None of this really has anything to do with the dealer. They can't change the numbers based on what the manufacturer did 22 years ago. They sold the RV, explained the VIN/SN to you and you signed a piece of paper acknowledging all of this, and apparently provided you with the proper information to get tags and title. Still unclear how the dealership screwed you over and should be avoided by anyone buying an RV. You did not lose your license either. I say those things because your posts are very reactive and subjective based on worrying and not understanding all the facts. If I were the dealership and I read this post I'd seriously consider it slanderous, especially given they have the documentation that you signed which explains all of this. Nothing about this is screwy or scandalous from the dealer. This has to do with how a serial number was documented by an Rv manufacturer 22 years ago.