Yep, and there were a couple of other aberrations as well, one of them the use of a M1919 Browning MG and not a Maxim.
But - 'The Spirit of the Game' would seem to indicate that we overlook these glitches as we suspend belief in many things in the movies we love.
What was authentic about the guns packed by Eastwood in the "Outlaw Josey Wales" ands other Spaghetti westerns?
Having made my point, my WB 1911 is a box stock, blued Remington RI. It came with a great trigger out of the box along with bevelled mag well, lowered/dimpled ejection port and hi-viz sights. Hardly a GI model, but it's the only 1911 I own that isn't set up for IPSC with all bells, gongs and whistles.