[Richard]

To me this is custom stuff. Expecting that parts will bolt on when you are mixing and matching is not realistic. To expect that a manufacturer can accommodate every possible combination is also unrealistic. I would clearance the bracket to fit. If you feel there is not enough left for strength add some metal to reinforce it. If you do not have the means to do it yourself find someone that can do it for you.
Looking at your pics again it looks like taking a moon section 1/2" or so out of the bracket where the tube is will let it bolt up. I would do it and not have a problem with it. Die grinder with a burr bit or a grinder should handle it. If you have to, cut spacer down for back bolt and use a shorter one. Bend an offset in bracket. Make it work.