Desperately need experienced opinions on Engine Identification

Okay, I have been scouring the fum here and the Internet in general, but I want second opinions on cast numbers for a 273 engine. This engine is 1,000 miles away, but I have a deal with the seller, and a relative is willing to pick it up tomorrow, so I have to figure out tonight if the engine is real or not.

The seller listed it as a complete 1967 273 Commando engine, plus transmission. He said he personally pulled it from a 1967 Formula S that he owns. Today he sent me pictures of the block and manifold casting numbers and they do not match. The block numbers are 2465330 (the rest is not visible), and 12-11-64. The manifold number is 2536563.

From my research this is a 1965 block with a 1966-1967 Manifold. I do not have any head numbers or other markings. I was told that the 66-67 manifold will not fit on the 65 block. I know it can be machined to fit, but it cannot fit without modification. I also heard that some parts from prior years could be remachined to build new engines in future years, but as old as this block is it seams very unlikely the block itself would have still been waiting to be built when the 1966 manifolds were in use. Also, the pictures show what appears to be 1967 valve covers instead of 1965.

I am afraid this is a Frankenstein motor where somebody has modified a 67 manifold to fit on a 65 block - perhaps to make it look like a Commando when it was a factory 2 bbl car.

Any opinions here? I basically have until tomorrow to decide if I am buying this engine and taking the risk that it is not the engine I was told it is.

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