Hey, a buddy of mine took an old "jeep trailer and pulled the tub off it and conv. it into a welding trailer. It had no tailgate and round fenders. The neighbor has one also which has been sitting out for years and the tub is shot. It has squared off fenders. They look really close to the same size, could I put the one tub on the other? What diff. are there. What should I look for? What are the similarities? Thanks.