Cub Cadet Sun Shade

I bought a sun shade for my XT2 a couple of years ago and I finally got tired of listening to it squeak and rattle. Decided I'd tighten up the nuts on the mounting plates on the frame. Three had stripped the threads and I couldn't tighten or loosen 'em, and the fourth one had seared off. Ordered two new plates ( because the bolts are welded to them ), four washers, and four flange nuts.
Was tightening the last bolt/nut and the bolt broke. Now, I'm 84 years old, not much stronger'n a kitten. Needless to say I was a tad ticked off. My young neighbor had helped me get the old brackets off, and he ground the bolts out of them. I thought about them when I went to bed that night after new bolt sheared.
Next day I went to Lowes and bought four stainless steel 1/4 - 20- X 1" bolts,four lock washers, and four nuts. Smoothed out the holes on the plate and put the new bolts through the plate and frame, then washer,nut on the bolt. THEN I put a second nut over the first one.
The frame seems more solid than when it was new. If / when the other side bolts break, I now know what to do.