71 C10 body mount questions

[jfalesi]

All;

My fuel tank replacement project has morphed into a fuel-tank-plus-POR-15-the-frame-and-maybe-replace-body-mounts project. I figured that while i have the tank pulled I might as well fix/update what I can see...

One of the rear body mounts came of relatively easily. The other three, not so much. Two of them seem to have some kind of sleeve sticking through into the bottom rubber piece. It appears to be metal. Is this part of the body? (see pics)

Is it feasible to replace just the rear body mounts, or should I just go ahead and replace them all at the same time, or alternatively, leave them all as-is?

Another question - any tips on getting the panhard bar off? Nuts ain't budging....

Thanks!
-Jamie