As previously mentioned as an indicative pricing and for interest’s sake, I don’t think services in Germany is feasible anymore once postage, VAT, duty and courier processing fees have been added
The first finned flange I posted a pic of (post #48 above) was quoted at €447 for 10 units
I simplified the design to the 6 fins you mentioned with a more ‘petal-like’ look, the price dropped to €357
I then smoothed all the edges that were feasible (without completely breaking the CAD model) and the price goes up again to €451
I also altered the flattened one after seeing your pics but didn't bother pricing, it'll be similar to the original 'Nasher design'
They quote €9 - €12 to 3D print a plastic 1-off, which could be used to test fit or as a plug for a mould, although I imagine casting four at a time would be the way to go… if my mate ever gets his 3D printer operational again, they’d be free though. I'd love to have a go at casting, when we can safely mingle and it's a little warmer outside.
On the plus side this is improving my CAD skills no end, playing with these and complex rocker cover designs,the Mag. finned ones look much taller than OEM, maybe to allow ridiculously lumpy cams? I haven't go one I'm ready to price for CNC yet, I just started with a square on photo of a gasket and superimposed the model over it.
I agree the easiest way to go, for casting, would be to start with an OEM one and stick MDF fins on/filler to make a plug, I'd also add 0.25-0.5mm to the gasket face so there's enough excess to mill off on the finished part.