thanks for the infoThe series 80 has a funky firing pin block. Part of the sear spring/frame/slide cutout arrangement. It makes the trigger pull quite peculiar -- not bad, just not right.
Someone makes a spacer to replace the firing pin block. Others offer hammers, triggers, sears, beaver tails, sear springs, etc. All over the internet available for your perusal. I would start with Brownell's, and have a look at their 1911 videos.
No special tools or jigs are necessary if you have a steady hand, good eyesight, and are handy with a file, straight edge, and a stone. (Stay far away from the dreaded Dremel Tool).
My Series 80 1991A1 Commander is a project gun, and although it shoots well, it cannot be converted to a true Series 70 model because of frame and slide cuts. It still shoots better and more accurately than any Kimber I ever owned.
To make matters worse, the youngun shoots it better than I can, and that always costs me a case of beer. At least he shares the beer!
It is no surprise Colt reintroduced the Series 70 some time later.