I started to rebuild my 46 V12 engine about 7 yrs ago and I got as far as getting almost everything done except the oil pump and the top part of the engine.

Due to health and money problems I never completly finished building the engine.I am now in the position to finish the job. The engine has been covered for all these years and I was wondering if I can just carry on with the job or do I have to start tearing it back down and start over again.

Theres no reason why you can't continue without re-doing unless the engine in stuck from sitting? Even then it might be ok if it will free-up without too much effort. If you are satisfied that the original assembly was done right and you used plenty of assemble lube, you should be ok. Rust is another matter depending on how extensive.
What do you mean by the "top part"? Valves and lifters?

I need to install the heads,carb and fuel pump. Also I am still not sure what to do about the oil pump,as there seems to be so many suggestions on what to use.

Thanks for replying to my question

Gerry

The original style pump used in your '46 engine should be Ok if it's in good shape, however, the replacement high volume M-15 pump would be the way to go. True, it was designed for flathead V8 racing engines with expanded bearing clearances and is probably too much for a standard Flathead V8. The V12 has a lot more to "oil" so the extra capacity will help maintain oil pressure when the engine starts to wear.

no matter what else u do.....get a high volume, high pressure pump from an lz vendor..I like Earle Brown..he will
help you, like a friendly uncle..call him