Flexi 3450 tank rebuild

Hi, recently started a big project rebuilding my tank. All new manifolds and seals etc. rebuilt kit for one of the meter boxes. Took back tank middle tank meter boxes out completely. Need to grind rust of and possibly grid some off where the boxes meet the hopper plates. Question has anyone done such a rebuild before. One thing I'm looking at is repaint the meter boxes and other items. Metal items I'm buffing and possibly sand blasting. The meter boxes are white metal and from what I read walnut shells would be the safest thing on aluminum. My original plan is once everything is cleaned to use a good primer then use boxliner spray/rubber guard. It got the smooth surface stuff. I'm thinking since a guy can't powder coat that this stuff may be very effective since it's very durable and can't see fert eating it away. Is this a bad idea. Curious if anyone has done a ptoject like this before? Thanks

Flexi 3450 tank rebuild