Not had a chance to fit, but to answer the question I stood it in place. It sits high and a little unbalanced so I know there is a small adjustment at the bottom. This is a photo of the top and you can see the radiator wants to sit deeper in the bracket.
Gut feeling is the welds top and bottom stop it sitting perfectly first time, and a bit of bracket bending (or the easier "trim the rubber"), will fix it.
Hoping to fit Sunday, and will report back, but I think it's going to be the easiest swap based on hours of researching Rover 213s and a dozen other cars that share a similar sized radiator.