I have one of the early Legacy 10-Wheelers, it's a pretty nice little locomotive. However, one characteristic has always bugged me, when you stop, the smoke fan stops, but the heater still runs. This will quickly cook the wick, and also I want it to smoke when it's stopped, it just looks better! It's a good looking little locomotive, so it was time to see what can be done.
I opened it up and extracted the existing smoke fan controller. It's a pretty simple design, just a dual 555 timer and a handful of parts. I'm not sure why they couldn't have done smoke at idle pretty simply with this much board real-estate. I mulled over the possibility of installing a Super-Chuffer. First step, I checked the wiring to the existing controller. It was conveniently labeled on the bottom, a 2-pin smoke motor connection and a three pin power, ground, and chuff switch connection.
WOW, simple and all the stuff I needed to wire up the Super-Chuffer right there in the pit under the smoke unit. After a trial fit to see if I could squeeze it in, I wired it up. The only additional wire I needed was the smoke heater power to enable the motor control.
I popped it on the test rollers and fired it up. Seemed perfect, chuffs looked great, smoke at idle, job well done!
I put it all back together again and hooked up the tender and ran it around the test track. One little glitch! Although everything was working, the smoke chuffs were not synchronized with the sound! 
Darn, I just realized that the Legacy triggers the sound on the opening of the chuff switch and TMCC triggers it on the closing of the chuff switch. RATS, I'd have to invert the sense of the chuff input to the Super-Chuffer.
Since the chuff switch has both a N/O and an N/C contact, that would be just a wire. I looked, and UGG! The chuff switch is buried under the boards, motor, etc. That doesn't look like fun. I took the coward's way out and just made a custom Super-Chuffer, a one line software code change inverted the sense of the chuff trigger. While I had it apart, I also added an LED headlight with Rule-17 lighting control, after all, it's practically free since I have the capability.
Put it all back together again and success! I have better looking chuffing, smoke at idle, and Rule-17 headlight operation. A little bonus is the amber LED I used looks great and it much brighter than the wimpy incandescent that was previously in the locomotive.
So... the answer to the question is, yes you can use the Super-Chuffer in a Legacy locomotive. This would be a worthwhile upgrade to many of the early Legacy locomotives that use a similar smoke controller and don't offer smoke at idle or Rule-17 headlight.
I've been wanting to give this a go for some time, just thought I should take a couple of hours of "me time" and do a project that I wanted to do. It was nice that everything needed for the install was centralized, and there was room for the board. This is another example of where the new board fits and the larger previous version would not have fit. It's a tight fit, but it's in there. 
