As I stated in a previous article, the Aristo mallet is a beautiful locomotive right out of the box.  I crawls smoothly along the track, and its smoke unit puts out prodigious quantities of smoke as it moves down the track.  It has a lot of added detail not ordinarily found in a steam locomotive at this price. (Around $600). After studying it for some time, I decided that some additional detailing could make for an even more prototypical model.  I bought the Southern Pacific Mallet, and feel that it is an excellent representation of the mallets that were delivered prior to being converted to the "cab forward" configuration by the SP shops.  I am not going to do this type of conversion (cab forward) at this time, but will be adding details to make the locomotive conform more to the SP "family" image.
    The pilot needs a coupler, and I added a Kadee #830 coupler, doing a  conversion similar to the one for Mikado which I wrote up in a previous article.  I then added a circular number plate to the smoke box which I purchased from Trackside Details (TD-19). I added numbers to it from some gold decals that I had previously purchased.  Everyone on the internet has criticized the classification lights on this locomotive for being red.  I corrected this by prying out the original red lenses, and adding clear lenses from Trackside Details (TD-36) which had the silver backing scraped off.  Two Aristo seated engineers were repainted and installed in the cab as engineer and fireman.  As a precaution, I used Blue Loctite on the screws holding the driver wheels in place, as I have done on all my Aristo steam locomotives. This prevents the screws from working loose over time, causing all sorts of driver and wheel problems.
    The tender was the next part of the project.  This is a beautiful model of a Vanderbilt Tender with six wheel Commonwealth trucks.  A Kadee #831 coupler fits on the rear perfectly.  I  ground down the original coal load and made a new flat deck with (.040)  styrene to cover the area.  I used a punch to simulate rivets on this piece and glued it in place creating an oil bunker, which is more like the SP prototype.  An oil  filler hatch from Ozark Miniatures (#0228) was glued on top along with a dipstick and curved vent pipe, which fabricated from styrene and brass rod.  As per SP practice, marker lamps were hung on either side of the tender on the rear of the oil bunker with the standard red and green lenses. (Ozark Miniatures #0093).    The tender comes equipped with a weatherproof speaker and PC board for powering a sound system.  I installed a Sierra Soundtraxx system which was optioned for an articulated locomotive.  You will need four chuff magnets to get the distinctive double chuff that an articulated locomotive makes.  This plus the battery fit perfectly inside the tender, with easy access to the option switches.  The tender already has a working backup light, so no additional wiring for this feature is required.  I trigger all of my steam locomotive chuffs from a tender axel to minimize any additional wiring, and I also mount a reed switch on the forward tender truck to control the whistle signal.  Aristo wires the rear tender wheels for power pickup, and this is run to the locomotive via a supplied plug similar to what the Mikado has.  The tender drawbar can be adjusted for length depending on what radius your curves are.  I have seen people using a small rubber vacuum nipple from the automotive store to keep the drawbar from uncoupling due to bouncing on uneven track.
    The final touches for this project involve the weathering of the entire locomotive and tender using prototype photographs.  I first painted the wheels on both loco and tender with Floquil Roof Brown to simulate rust.  The loco drivers were then painted with Floquil Engine Black to cut down on the unrealistic metallic shine. I ran the locomotive slowly in place and airbrushed Floquil Earth along the running gear, on the pilot, and along the tender to simulate road dust kicked up on the main line.  I made up a white/gray wash from an acrylic paint thinned with alcohol, and brushed it down from the six wash out plugs on the boiler, the whistle and the pop valves.  I airbrushed some of the same color in these areas to simulate the deposits left by condensing steam. This wash was also used on the tender to simulate where water has been spilled on the deck and has run down the sides.  Some rust is applied on couplers and in appropriate places  on the loco and tender, and the whole locomotive is sprayed with a light coat of Floquil Dust.  I then air brushed Floquil Grimy Black around the stack and smoke box, along the top of the loco, and on the firebox sides.  Finally I use Floquil Oil to splash around the oil filler and the top of the tender.
    While these are mostly cosmetic changes, the effect is very dramatic when compared to the look straight out of the box.  This locomotive now matches my fleet of SP steam locomotives more closely, and it sounds and looks great running with a long string of freight cars on my layout.