You might try researching some of the craft sites. Large bird houses of this type are more generally used for decor rather than for birds.

Or do a search on bird racing for dovecots.

Vernon, Here is one site you can check. I just want to caution you that it is important to monitor the house so that house sparrows don't nest in it. They are non-native and will kill native birds. I would actually recommend plugging the hole if you can't monitor it. Otherwise, it does more harm than good.

Here is a link that might be useful: bird house plans

I stumbled upon the site for bird house plans and was much impressed. Used it to build a screech owl house. They, apparently, don't know it yet. Am ignorant of any website that gives directions to houses primarily decorative.

any other ideas? So far I've just found what I would call normal large birdhouses...nothing like you'd see on a really nice 'estate' type property. Appreciate your help.