I've been seeing a lot of places describing all 1911's made before the Series 80 as Series 70.
That's not right. The series 70 did have some changes from the original Gov't Model.
The barrel bushing with the collet fingers is the main change. That bushing was continued into the first part of Series 80 production as well.
Current "Series 70" guns from Colt don't have it. Go figure.
I am also bemused that hardly anyone kept the arched mainspring housing and short trigger of the M1911A1 but did keep all of the other changes.
The winds of fashion blow and we must bend or we will break. And go broke keeping in style!