I have sent about 4 email's to Bullet, and not had one reply.
Again it looks like a well engineered manifold, and at a very reasonable price, but not much use if they don't reply to my emails.
Finding the foundry that cast Richwoods manifold, would be very difficult from the UK but not impossible, but I'm fairly sure that unless you owned the rights to the manifold, the foundry shouldn't be casting it for just anybody.
However if I could find them, they might be able to point me in the right direction.
I have been thinking of making my own manifold, and will probably end up doing it that way.
Watch this space.
Thanks,
Iggy