Ok, so I figured out what the cause of the problem was.

If anyone ever had doubts about the evils of lift blocks this should further erase them.

Upon closer inspection, the lift blocks are at least partially hollow, so the part that is resting on the perch is just the outer edges of the blocks (which probably resemble a box) are resting on the perches. At the front of the perch, the blocks have squashed the outer edges of the perch and have kind of slumped over the edges of the perch. Unfortunately too in the process the perches have been damaged so they'll either need repair in the form of welding build-up (?) or replacement.

I'm leaning towards replacement because then I can get the pinion angle just right with the new springs in place.

Thanks for your help.

Chip

P.S. Here's a link to a bigger/better picture of the boxy type blocks boxy blocks and the damage done
You can see how the inside on the rear was chewing away on the rear part of the perch.