How to replace the rear cab mount brackets

[Damien8086]

Hello,

I have a 1970 C10 CST and I had ordered the cab mounting kit from LMC in hopes to replace the worn out hardware and cushions on my truck.

Unfortunately once I got in there I found that the hex bolts that I took off of the rear appear to actually be the same size as the larger hex bolts that come with the kit that are meant for the front of the cab. Also the upper cushion does not really resemble the replacement upper cushion that I got with the kit. Worst of all the driver side rear bracket is completely rusted out. At some point someone appears to have put a couple of metal plates on the top of the cab mount bracket attached to the frame to (I guess) work as shims and to make up for the rusted out bolt hole in the bracket. I have attached some pictures.

My question is how do I replace the brackets themselves? I see a lot of posts about doing the cab mount kit job, but very little about the brackets. Is this a job that requires welding experience (I have none nor the tools)?

Thanks for any help that you can provide.