These people can be hard to find, especially since one can cover multiple states. I find it best to go to a local modular home seller and ask them what or who they recommend. Be aware that these people aren't cheap, and I've seen the situation where the cost of their services was more than enough to make people just walk away from the situation. They are mostly about selling new and not fixing. The specialists you are looking for mostly do warranty work, and that's why they are harder to find.