Is it feasible and at what approximate cost to print aluminum cylinder heads for antique Rolls-Royce six cylinder engines. Many of the existing heads are rotting thru the water passages and becoming unrepairable. A few have been reproduced by casting but there are a number of different engines and heads in use. Heads vary from 30-38" long, about 8" wide and 5" high. Up to 100 copies of some of the various heads would need to be produced and finish machining for valve seats and guides would be negotiable.
AFAIK, the same third-party specialists - once clustered in the North of Italy, or North-East Spain/South-West France...might STILL be? - who make the goods for easily half a hundred different present-day aluminium heads would be the go-to.
Whatever it is that works for prototype, to limited-production race engnes, to mass-production basic transportation, they are more than just a hundred years as good at it as ever was.
Possible exception early BMW SOHC six - one of the most notoriously bad 'loominum head casting designs. Anywhere. Ever.
Thereafter? Nothing "new" to it unless they've found "new" useful.
It's their Day job, Basque country or Northern Italy.. and for a coupla thousand years arredy, sand, "lost wax", "lost foam", 3-D cores... wotever suits, prehistoric times onward.
And "it's only MONEY", but beating their prices is probably going to cost a great deal more in the attempt than it saves.
Beating "the experience" is never cheap!