Thanks for the kind comments guys! I've done a lot of custom paint of derelict Lionel cars and really enjoy my unique creations. One example is that I've made custom cabooses to match all of my PostWar diesel engine schemes. I've also restored PreWar standard gauge trains.
Ray, custom decals are easy. you can print any design you can find on the internet, any font lettering you may have in EXCEL, WORD, etc. Only issues are that you can't print white, and lighter colors will not be opaque enough if applied to darker backgrounds. You can print large or small, an example of large are the American Flyer decals I printed for the display I made and shared on another post here about my American Flyer Alcove.
I buy decal paper on Amazon, comes in clear background or white background. I like that sold by World-Paper. I'm sure that you can find instructional videos for waterslide decal use on YouTube. That and a clear spray, like that made by Krylon that you can purchase at Home Depot or Lowes, is all you need.