Depends what for, currently sold shutters, or an old barrel lens. Teamwork might have flanges for current shutters, if barrel lenses try Aperture, Mr Cad, or phone Peter Walnes, or place a wanter advert on this forum
SRB can certainly make the flanges but the cost of a one off is quite high. However the price would drop significantly if a few were made at the same time.
I had thought of canvassing to see if anyone was interested in a group order, but there's so many different flanges.