GrimJim,
I've shot Colt 1911's for years. The NM on your barrel indicates National Match. Over the years, since the NM was introduced,as a MK IV, prior to series 70 guns, it was called simply a National Match. Soon after that, the Gold Cup was introduced, and the "NM" was incorporated into the Gold Cup descriptor. A little later, in the late 70's I think, the word "Trophy" was incorporated into the descriptor for what was Colt's premier target 45ACP.
Your gun will have the Eliason rear adjustable sight, the flat rib on the top of the slide, and the wide ribbed adjustable trigger. It should also have the conventional spur hammer.
The internal parts on your Trophy marked NM are very likely to be the same as the goverment model 1911's, except hand fitted to tighter tolerances, along with a tighter slide to frame fit, and better barrel lockup into the slide.
The early MK IV NM guns had an extra small spring on the lower right hand corner of the sear that helped to set the sear on the hammer hooks with very light triggers. I believe this feature was discontinued in the 60's prior to the release of the series 70 guns, althought, you may find a transitional series 70 with this feature.
Somewhere along the line, the collet barrel bushing was added to the design, but that didn't last very long, as they were prone to breaking with "full house" loads.
Around the time of the 3 year strike at Colt, the Gold Cups suffered, by being built with pretty much the same inner parts as the Goverment gun. This was done as a cost savings, and a convienence. I don't know what the parts makeup, or quality of fit is on the present day Gold cups, as I have not shot, or handled a newer one.
None of the above guns had a firing pin blocking safety system, as this feature was not added until the series 80 guns came out.
I am recalling all this info from memory, so don't hold me to the letter on all this. Some one else may have more info for you.
Tom
