Dave (and others), Don't worry about the Argyle being obscure and no one treading that water before. Clearly, I'm not a big fan of leaving any steamer well enough alone. (Vance - it was a Dylan.) Imagining something as something else takes x-ray vision.
The key to any locomotive kitbash is to take away everything that doesn't look like what you want. Sounds reasonable, but many folks get hung up in the extremes this sometimes takes them to. Quite often, you'll end up stripping the locomotive completely down to just a boiler and chassis. While it may seem like somewhat of a waste of money to buy a locomotive and discard everything but the essentials, you actually gain much more in the process. You end up with exactly the locomotive you want, built on a proven (in Roundhouse's case) boiler and chassis that will give you years of enjoyment. To me, that's worth much more than what you originally spent on the locomotive in the first place. Many times, though, people stop half way through the process of tearing down, and say "that's far enough. I can go from here." The results are often something that looks slightly different from the original, but no where near what the builder really had in mind. In most cases, simply raising a headlight or adding an airtank here and there is "sufficient." To me, that's a failure to realize the potential a particular locomotive offers. The best locomotive rebuilds are the ones where someone asks "did you scratchbuild that?" As "the other" Kevin said, Alan Olson is perhaps one of the most renowned gurus in that department, and a source of inspiration for a good number of my models. The other half of this equation is to not be afraid to re-build a locomotive once you've already kitbashed it once. My Lady Anne conversion underwent a facelift before last DH, giving her new domes and a new cab. These were things I wasn't 100% satisfied with the first time around, so they got redone the second time, correctly. My Dylan kitbash is likely going to undergo a similar rebuild sometime in the future. I want to backdate her with a new headlight, domes, and cab. Quite simply, I'm not 100% happy, and all it takes is a little time on the workbench to make me 100% happy. I'm not aware of too many 0-6-2 locos in the American narrow gauge scene. The only one I can think of is the Uintah's #20 and #21. They were inside frames, where the Argyle is outside, but I can't imagine that being a show stopper. It did have very neat, rounded side-tanks. (A pattern I duplicated on my Dylan bash) Actually, the lines of the Argyle are very similar - right down to the capped stack. Plans for this loco can be found in Mallory Hope Ferrel's "The Gilsonite Route." The key is to find something you want to build, find a locomotive that comes close enough in all the key dimensions - wheel arrangement, driver size, boiler size - and go from there. And when your spare parts box gets full, take it to the next steam-up. There will be plenty of folks who will help thin your "spare" collection. If you get stuck along the way, don't hesitate to ask... While many of us have likely not embarked on your particular project, we've probably done very similar things in ours. We'll be more than happy to help you over the hump. Later, K