Getting my Mk IV Series 70 Gold Cup National match ready to sell, and I'm putting back the original springs and grips. I'm putting the trigger spring housing back after changing the spring, when something goes horribly wrong with the combination spring. There's a click, and suddenly every function of the fire-control system is locked up. I've never taken a 1911 down past field strip, but I got a feeling that I was getting ready to. So, I went and got the book and started in. All that happened was the spring had slipped out of it's indexing slot and moved down a little - just enough so that when I pushed the housing into the frame, the left finger of the combo spring with the hook on it snapped into the wrong place and jammed the sear. I had to take the grip safety out to see what was going on. Got it fixed just fine, with no damage to anything. I did not want to be the guy taking a bag of parts to the gunsmith. Particularly when I wanted to take pictures of the gun tomorrow.