Westerbeke W70 block manufacturer?
 

I have a Westerbeke W70 engine, circa 1987. The exhaust manifold seals
were leaking, so I removed the manifold; and in doing so, broke one of
the exhaust ports (one wall was less than 1 mm thick -- not a good
augury for the life of the engine). The Westerbeke parts suppliers
don't carry exhaust ports, as they're associated with the block, not
the rest of the engine. This leads to a number of questions:
(1) How do I find out who made my block? Is there an identification
tag or casting? If so, where? The only casting I can find says
"121362", with no other identification.
(2) The broken port is cast iron. Local artisans can build me a
replacement out of stainless steel, or out of chrome-plated steel. Is
there any reason not to use these materials?
(3) I can also get an exact replica cast for about $200. How does that
compare with the price of a new part, assuming I could find one?
Rob
Marmaris, Turkey