I have a pair of MTH Centipedes that came to me converted from PS/1 to a TAS EOB TMCC setup. However, the whole effect was less than perfect, they didn't run that well, and the smoke had one speed, Frog Choker! Of course, the sound was also Generic Diesel, I'm actually a bit tired of hearing the same diesel sound from a ton of different locomotives. Finally, the lighting was pretty poor, and I like having high quality LED lighting. Also, the automatic cab light control and Rule-17 lighting that's standard with the RCMC is a nice touch. I also wanted these to be independent units with complete electronics, no unsightly tethers, etc. I decided it was time to improve these.
I selected the Legacy Centipede RS-Lite sound boards, one for each unit. It was nice that the actual sound set for this specific engine was available. I also had in stock a pair of RCMC boards with both smoke unit outputs enabled, that was essential since each of these has two smoke units.
First step was to strip everything off the chassis, then drill the slave chassis for the speaker holes since both units will have sound. I also drilled and tapped holes for the speaker baffles and of course, the RCMC mounting. The switch provisions were conveniently there, I had four switches to mount and there were four locations for switches!
I also took the rear pilots that had the oddball scissors drawbar and the Dremel removed all the inside posts and mounts from the pilot to make room for the standard electrocoupler attached to the pilot truck.
Next to tackle a couple of modification tasks before mounting everything. The smoke units were all a little rough, so they got the proper resistor, new wick, new gaskets, and a couple of them got new motors. I was fortunate that this set didn't have the zinc rotted smoke units that I've encountered in a few PS/1 diesels lately.
Of course, one of the motors for each unit has to have the Legacy tach encoder and flywheel, so those were installed next.
With the preliminary work out of the way, I mounted all the parts back on to the chassis, here they are mechanically complete. Not exactly ready for their first track test yet, next comes a harder part, building a installing all the wiring harnesses and lights.
The first "completed chassis off the line, everything wired and tested. Since all of the lighting is installed on the chassis, the shell modifications consisted of adding a long wire Legacy antenna. I also repaired some mounting posts, they always seem to have some cracks in plastic stuff that's 25 years old. There's actually quite a lot of wiring in a Legacy engine.
All together and ready for a full track test, four feet of engine ready to haul whatever load comes their way!
OK, their first load was a caboose, but it's the thought that counts! 
I programmed a lash-up and everything worked perfectly, I'm pleased with my new Legacy Centipedes.
