You need a 10 tonne press I think, but give it a go for nowt.
It's not the flang ethat does it, it's the hardness of the polyester material used, especially as you Defender has the softest rubber bushes fitted, they are not as stiff as the later RRC "double" bush and are narrower than late RRC and Disco. I think they are the original RRC bushes :-k
Anyhooo, you've gone form one exteme to the other.