Is this SN Colt 45 A WW2 Issue

Try running 1810431. Leave off the G, and the dash. I just did on the Colt site, and it came back Model 1911A1 Military, year of manufacture 1944. So it sounds like a legit "original issue GI pistol," but that just my opinion.

A legit GI is not serialized G-181043-1

If that is actually the way the gun is marked, it is not right.
A legit serial number would read "No 1810431".

You sure its not C-1810341

C prefix ended in the 240000 range.

Jim Watson said:

C prefix ended in the 240000 range.

Click to expand...

You're right, too many digits,

There are a bunch of images on WW2 Colt M1911's

Some excellent pictures here:

https://www.rockislandauction.com/d...olt-model-1911a1-us-army-semiautomatic-pistol

The markings for a service pistol should match

Might be an aftermarket frame with a USGI slide.