Any machine shop worthy of the name should be able to make things like that. It looks like you need to find a better machinist. Once the rough-poured bearings are in place, you'll still need to line bore them to fit the crankshaft. Can the shop you're dealing with do that? All the poured main bearings I've ever worked with, like Model T and Model A Ford engines, have the Babbit metal poured directly into grooves in the block, using molds designed for that purpose.
Jerry

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