Everything you said is right, but :) I'm not keen on stainless, it's too hard for me, but mild will rust like a bastard :( A laser cut flange would be perfect, but I don't think you understand just how tight I am, part of the fun with the car is doing everything as cheap as possible, even if I have cash burning hole in me pocket.
On a similar note, my 99p carbs arrived this morning, what a gorgeouis smell to wake up to :)