The only major differences between a 1960's Python and the Python Elite are:
The Elite has a new style thread barrel, and a single pin in the front sight.
The single pin was both a cost savings, and a method of identifying a new thread barrel.
The second big difference is the Elite stamp on the barrel.
The post mid-1970's Pythons had a different internal ejector and rod assembly.
Most people will say that the older Pythons were better quality with a better finish.
As far as actual physical differences between older and Elite Pythons, the Python changed remarkably little over it's production life.
The very early Pythons had features like a slightly different top rib, and a hollow under lug.
By the mid-1960's these were dispensed with, and the Python changed almost not at all thereafter.
A 1960's Python and an Elite Python mechanically are indistinguishable.