The Big Dipper made a chair and a ring. How to fix it?

The seats are the same model and cannot be mass-produced. The Big Dipper is a wonderful model. There is a data that the seat of the Big Dipper is 4-5 cm. At present, it is known that the original seats of Converse, Qi Jun, Sylphy and Jeep Freeman can be installed perfectly. With a 4 cm wide flat iron as a support, you can buy about 5 meters of scrap iron. Anyway, you need to paint after welding, and the bottle with 5 yuan needs to be hand-painted.