Elgaucho
Back to your question. You have a lot of questions you must ask.
You need to know what that train is worth now in the present condition. EBay completed auctions may help
You need to know how much it will be worth in refurnished condition (many antiques are worth less when fixed up or modified)
You need to know what it means to you, say does it have sentimental value to you
What train could you buy with the money to fix up this old train?
Charlie