In addition to the other caveats mentioned, how do you plan on registering/licensing it? If it's a bare channel frame with axles, it probably has no VIN. Without a VIN, it can't be registered....nor insured.
If you fix it up and want to register it, it will have to have everything the DOT requires, because it's going to need to pass an inspection to be issued a VIN.
Just so you know, one common stumbling block with MH axles is the width. In most states, the maximum trailer width dimension is 102". Yes, you can cut the axles and splice them back together, but that also means your spring perches aren't going to line up with the trailer frame any more....so they'll have to be moved.
If MH components were high quality, AND you had a lot of free time....it might be a worthwhile endeavor. MH stuff is not high quality stuff though. You'll surely be told otherwise, but there's plenty of evidence straight from the manufacturers that says otherwise.
Simply stated, the same manufacturers that build MH axles also build *real* trailer axles that are suited for daily use. There would be no reason whatsoever to separate their product lines into two categories.....if the MH stuff was up to the task.