Mancini rocker questions...

You don’t want to grind on the hold downs. I think they are just anodized aluminum. Which means they are only surface hardened. Grind on the spacers if you have to. Centered left to right is not super critical. As long as the spring or pushrod doesn’t hit. If you do grind the spacer on a belt sander remember to rotate it 1/4 turn in your hand and touch it to the belt, repeat. It will help keep the sides paralleish. If you don’t, it is very hard not to angle it. I would almost avoid the belt sander and tape some sandpaper to a flat surface and do it by hand.