Mobile home axles are not worth rebuilding. They are built to last only a few hundred miles. You would have to replace everything on both ends of the axle, and they may be a diameter that only mobile home axle components would fit.
Better to buy new axles. A 3,500 pound straight trailer axle with idler hubs is only $104.95 per axle, plus freight.
Installing new axles without brakes is not a good idea, when the ones with electric brakes are not that expensive. A 3,500 pound straight trailer axle with electric brakes: $256.95 per axle, plus freight.
Determine the width of the axle you need (measure mounting face to mounting face) and order new ones at the prices noted above from SouthWestWheel's trailer supply store at:
Trailer Axles for utility and boat trailers
And while you're deaming, consider upgrading the axle(s) (and wheels and tires) to handle 5,000 pounds instead of only 3,500. Everything you need is available at trailerpart.com
