On those slide release bars, sanding them down and repainting them is a viable option. Like Jon said, be careful removing them as I don't know how frail yours are with the rust on them. If you get new rails and put your reconditioned slide release bars in them, it might work out just fine for you.
I managed to secure a set from a parts car early on when I just got my car. My car didn't come with any believe it or not and with the driver's seat being about 2-3 clicks more forward than I needed it, you can imagine what was going through my mind as I thought I might have just bought a car I don't fit in. Luckily it was just the bars missing and probably just weren't reinstalled after the seats were out getting redone.
I cleaned up a used pair, repainted and have been fine since.
Attachment 26736

