I just replaced about 10 of mine in my '76 SOVEREIGN
rebuild/rescue. What I opted for was to use 1 1/2"X1 1/2"x1/8" angle and bolt them to the frame & new outriggers. Use grade 8 bolts with nyloc loc washers & nuts. This will eliminate concerns with creating weak spots in the frame by applying more theat to that same area. Plus you can do this yourself. With you floor out(surely this was rotted away as well) you can access these areas. Be sure to use levels,squares and straight edges to align these. You'll also find that on the good ones, that the factoru did a lousey job in aligning all these outriggers. Some are low & some are high. When finished you'll have a straighter body.