roller to bunk trailer--Who has done this?

[Starzofchaos]

The keel roller is a 12" thermal plastic roller from yates. I can tell where it took off the gelcoat due to some left over paint embedded in the roller.
After the weight of the boat sitting on the roller for a while it developed a flat spot, and its starting to bend making it hard to roll.
So I got a few choices left, either replace it with a self centering polyurethane roller or do away with it all and do the brackets and bunk board. Or add in another cross beam aft and keep the roller to help center the boat. Either way I am looking at 100 bucks to fix this problem.
I noticed in the past that the 3x3 tube the I beams connect to sits almost 4" forward of the roller cross beam. I can tell it has done some damage in the past. I've looked at other Aluminum trailers on the internet and seen that this tube doesn't extend nearly as far aft as mine does. This is the reason that we had to keep the keel roller so it doesn't contact the tube. I'll go this weekend and get the boat off of the trailer and take more pictures.