I've had an MTH RailKing Pennsy L-1 laying around since 2000. It has gotten very little track time, as we run predominantly prewar gear. It's a LocoSound version, so none of the vagaries of ProtoSound...no batteries, no clinking-clanking, just smoke and an elementary, albeit horrific, sound board (which fortunately can be turned off).
I'm not particularly fond of Pennsy equipment, although the bulky/hefty appearance of the L-1s Mikes and the I-1s Decs have a certain appeal. This one, out-of-the-box, sported a gunmetal-and-tuscan scheme with bright, nickel-rimmed drivers and running gear, just the antithesis of any photo I'd ever seen. So, without hesitation, I asked Sarge to filthy it up for me, i.e. make it look like it probably did the week before it was retired.
I'm quite happy with the result. Here's a couple pics Sarge sent me in-process to assess the filth:


Here's another pic I took when it came home:

A proprietary process developed by Sarge...less-is-more, he describes it, and I would agree. Its sitting on the layout now, curing. I plan to hit it with a couple oversprays of clear matte to protect the finish, as it will get a bit of handling. Hopefully we don't bark it up too much.
I doubt much 3-rail passes through Sarge's paint-booth. Brilliant...thanks mate!
Paul