Conundrum with my new Rad, opinions?

[CRGRS 66]

Received my new rad, and have a couple of issues. The top and bottom tank are both wider than the original, and the overall rad is narrower than the original. I think I am fine to trim the rubber on the two bottom brackets, but the top brackets would need trimming, along with the rubbers in order for it to work. See the pics where there is space between the rad and the support to rad seals. Should I center it? Should I mount it to one side and fill the other side with some square tubing, or angle, or should send this thing back?