I thought I would need to use PolyFilla just to level the pf paint. If i'm reading this right I can just use primer 
We are referring to the playfield ?
Replace chipped or missing paint with paint. If the area is exposed (bare wood) then use primer just to create adhesion for the paint to "grab" on to the playfield. Build up the area with coats of paint. Sand and level.
Maybe post some pictures of the area ?
