I have a 20" Class B motorhome, a van camper. When I wanted to buy it I found out my city had an ordinance forcing them to only be parked behind the house out of sight from the street & needing a permit for that. Since my house had no way to get the mh behind the house I drafted a letter to city council, before I bought it, with a pic asking for permission to park it in my driveway. The city clerk had me go to the building head. He said it would be considered a conversion van & OK. Three years later the city passes a new ordinance eliminating the permits and totally banning mh's, etc. I was given 10 days to remove it. Over 100 others were cited for their mh's, tt, boats, etc, that were under the permits. I filed for a variance. Neighbors came with me & spoke to council then. I showed the copy of my prepurchase letter & explained I was not covered by the permit process. They said I needed 5 of 7 members votes. Only 6 were present. I got 4 votes & was denied. That really got me angry.
I spent weeks doing legal research & found many interesting things. A similar case in Ohio was fought to their supreme court & they ruled that homeowners have the right to park in their own drive. So no city can deny mh's there. I found similar cases in my state re heavy trucks etc. I found an attorney who helped me file a court case. I did all the work & research. I tried to get some of the others affected to go in on this. None wanted to be a part. State law said this could be fought if not too much time had passed.
While this went on I got very involved with city politics, appeared at every council meeting for 2 years, and worked with the more liberal minority during the next election and helped get newcomers elected & the liberals got in power. The city now said they'ld give me a variance if I withdrew my suit. I did, & they approved me 7-0. I spent less than $1,000, but the city spent over $10,000 fighting me. If had the financial & legal support of the other affected owners I may have gone on with the case to throw out the new ordinance. But since I could not get in under the old permit system & the others would not join I went with the variance.
My only slight concern is I can't replace my Class B with another without going for another variance which they would not grant. I plan on keeping mine forever, even replacing the engine if needed.
I learned much about legalities of getting a variance, court cases fighting this & more. I got advice from FMCA and Good Sam. I tried to get MH mfrs involved - They refused. I really think if we had gone all the way to our state's supreme court I would have won & MI would be like OH.
The OP's situation is different as this is an old ordinance. You will never win a selected enforcement argument. Never show examples of others doing it as you're really just turning them in. This took my constant attention & work for 2 years. Good thing I retired early. If you are not ready to do that & get involved politicly, you have the 3 options: store it, sell it, or move.