And here's the donor!
These 'Light Action' derailleurs are the cheaper little cousins to the 700CX fitness group derailleurs, and the precursor to the RX100 long cage stuff available a few years later. Similar in quality to the Deore LX and Exage 500LX derailleurs available in mountain groupos of the time, these guys get no love today...
But there's a secret...
They are nearly identical to Deore DX short cage derailleurs, and where they are different, they're made of steel. Darn strong steel.
Plus...the whole Light Action moniker is a total misnomer, as they have a very stout return spring and snap off firm shifts even when caked with muck or pranged on something hard.
So, Deore MT60 parts in one hand, and a rusted solid, filthy Light Action in the other, I got down to business and put together a solid unit, ready to serve urban bike duty and be beat to a pulp...a fate I'd never deploy one of my Deore DX units to undertake. Is it pretty? Sort of...the pictures show much more degredation to the finish that the eye reveals. But is it functional? 100%. Straight and strong. Compatible with all Shimano 7-8-9 speed mountain groups, max tooth 28T. Go ahead, beat it up!
If you see these Light Action units kicking around somewhere in a parts bin or on a well worn fitness bike, don't pass them by. These things make for niceshort cage mountain derailleurs on a budget.