An alternative I used with a Centec I used to own, and for which I had to make a support bracket, would be to re-bore the bracket slightly over-size to take a new but concentric bearing.
Having rough-drilled the bracket, I fitted it to the over-arm, then slacked the over-arm clamps just enough for it to slide.
Next, I carefully clamped the bracket to a slotted angle-plate bolted first to the table, with spacers to allow the boring-tool to emerge.
I could then finish-bore the bracket with a small boring-head, taking only light cuts due to the large off-set loading on the cross-feed – not only the cutting but also pushing the heavy over-arm back.
(Why not keep the arm tight and slide the bracket? To give a much more stable travel.)
I have a Denbigh H4 horizontal mill, of similar size to the Centec but not as refined, and will adopt the same process for the new drop-bracket this needs.