The faders on the 1280 console are one of its most fragile electro/mechanical components, considering the amount of use they get and the fact that the potentiometer body has an open slot that invites all sorts of dust and moisture.
You can see pictures of the condition of some corroded faders and the wear and tear they accumulate with time here. "Cleaning Faders"
The faders installed in the 1280 are:
Manufacture: ALPS (Japan)
Part No: 79G-10kΩA
I could not find anything within the catalog of the most popular manufacturers that would exactly fit. The travel distance of 60mm is a format that apparently is not used often on a large console format, it may be used on smaller equipment so it is difficult to find variety through the usual distributors.
ALPS does have a part with the same travel, resistance and taper, but it does not have the same lever type.
Matt found a potentiometer in the Bournes catalog that fit all the specs with the exception of the distance between bolt holes as you can see below.