Gene,
Hate to tell you but I recently sold one that I built from the Woodland Scenics kit that looked pretty good. Do yourself a favor and look into the N scale water tanks. This one would really look beyond your wildest imagination for scale, it's big even for HO scale. It would be bigger than some of your engines, and it is a difficult kit to build; all metal and wire and needs filing and stuff you haven't tackled yet.
Do a search on Walters for an N scale water tank. There are lots out there. Actually, if you are concerned about the yard, all you need is the water spout somewhere in the service tracks. There are lots of those out there. The piping from the off site water tank is underground.
Oft times the tank was behind the roundhouse and the engines never had access to the actual water storage.
Gene, I know you mix scales, but take my word for it. This would look very odd.
B-) & :x
