Here's another option, if you're not comfortable attempting such a repair on your own. Back when I was running the connecting rod reconditioning department for a big machine shop in Nashville, we sent our cracked blocks and cylinder heads to a company called "Diesel Cast Welding". They have a dedicated department for antique and classic car parts. The company has several facilities around the country. I'm not sure about their pricing structure, but it's probably a good way to salvage scarce, high-value items.

https://www.dieselcastwelding.com/

Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!