Flange form forgetfulness

"Once that's done the basic frame on which to hang all the other bits will be pretty much finished" he said. Ah, forgot one major task; filing this new part so the flange is a 'rounded diamond' shape. Thinking about it it'll probable be easier to make the matching gland at the same time i.e. before solding to the frame, as the pair can be fixed together and filed/drilled as one. Need to make another widget though as they have different bores...