[villagetinker]

David Moon, very nice work these look very good. To gauge your demand, I would suggest possibly providing some additional info, like:
Do you clean up old photos, remove scratches or folds, stains, fading?
Do you provide other services, like digitizing photos?
Do you provide digital copy, or a finished print, or both?
Does the person have rights to make additional copies of the restored or colorized photo?
Do you have a price range in mind?

I think there is a local organization that helps setup small businesses, I cannot recall the name, maybe some one else can provide that.

On a side note be careful of the restrictions of running a business out of your house. I wish you good luck, as I think you may have a service that is not generally available.
Hope this helps.