Welcome aboard 1st of all.
Sad to say but I think the only way you are going to find exact replacements are either by finding them used or back to the dealer for those brackets. Why do you want or need to replace the brackets?
Wobble roller brackets are not as interchangeable as bunk board brackets. If both sides do not have the same geometry the boat will not sit correctly on the rollers and could cause serious damage. If he has to change one side with a different type then I would suggest that both sides be changed with identicle units. The wobble rollers thenselves aren't the problem, it's the bunks.