Here is a photo of the board after sanding, oiling and waxing. Did it need a refurb? There were some deep marks that needed to come out but overall it was still in good shape after three years of duty. Almost looks new.
4 x 24 belt sander with 60 grit, followed by 100 then 120 grit. Random orbit sander with 100 then 120 grit followed by a 1/3 sheet pad sander with 120. Used a lot of the eraser stick to clean the belts and pads since each clogged quickly. Then soaked in the oil bath, allowed to drain overnight then waxed.