Opinions on rusty trailing arms

[Todd Hepler]

I've started a 72 GMC swb project with a couple of craigslist donor trucks. I have spent a couple of days cleaning up the frame and came across some questionable areas I'd like some opinions on.
Trailing arms - the drivers side is starting to rust in between the two halves to the point of swelling the arm - is it too far gone?


Also - the plate above the upper spring perches is doing the same rusty swelling as the trailing arm - what are these plates called and where can I get a pair?



Thanks for all your help
Todd