The old idlers have beat and wore an area of the track frame from flopping and bouncing which im sure is normal ware. How do you repair the track frame before installing the idler. Can you just lay some beads and grind it down flat? Do you cut and weld back in a section? Do you not worry about it and let ot go as is. Im not a mechanic by trade but I have wore a lot of iron out.
You're on to it @Robin peter ! Weld the worn areas & grind flat. There is a replacement wear strip under the upper edge of the frame, if not done yet & it's not too worn, you can flip it over for a fresh edge. Be sure to order the 4 x rubber coated springs to go into the carrier. Often the standard square plates under the springs are too thin & they will fall out after a short amount of time - fabricate some slightly thicker ones to make your repair more durable.
Thanks for the help. I'll make a thicker plate for the rubber pads.