1) Trijicon's standard nite sights offer a good sight picture without messing up the lines of a classic Colt 1911 too much, and also don't require a ton of milling and the consequent refinishing of the slide. That's why they went on my pre-Series 70 Colt, and now my roomie's has them too. We'll be like the Bobbsey Twins!
2) The MGI QCB upper that I traded into was a big hit.
3) Did you know that a Colt 1903 Pocket Hammer and a Colt 1902 Military have takedown plugs that look nearly identical, except the 1903's is shorter. This means that if you whittle the 1903 plug out of drill rod, it won't be long enough to use in a 1902 and you can't exactly add metal... So you have to whittle a second plug.