Gentlemen;
There are no 'new' ones without spending a bundle, which is not needed. As 'out of ballance' as the 'stock' engines are, they don't turn fast enough etc.
Anything from 1937-62 works, with a few exceptions. The 'small' belt ones started around 1950 & go till 62.
They can't be chromed because there 'vulcanized'.
Call Patrick's. I'm sure he has several.
Good luck