stepnmud, you will find the lever safety to be a slightly different mechanism, and certainly a different spring than the 73, which is more like the original Winchester. I have an old Navy Arms 66 with the old Uberti lever safety, and it had a broken spring some years ago. Since no parts were available, I bought a Henry trigger, trigger spring and screw then machined a seat and screw thread in the receiver for the Henry trigger spring to get the gun working again.
Now, I understand, VTI has parts for the old Uberti lever safety.