tomc,
If you are contemplating doing the work yourself, this may be a fun project. If the dimensions with the added on spacer make the stock fit you, you can use the stock for a pattern to have a buttstock replicated. This would cost you about $125 or so for the machining plus the cost of the wood. The wood could be pretty cheap, maybe $25-50. Then you would need to do some fitting of the wood to the metal and sanding and finishing of the outside. The barrels would be rust blued, which you can learn to do with only a stainless tank and a stovetop along with some sandpaper and elbow grease. Refinishing the reciever is a bit more involved but you can prep the metal and send it for color casehardening for not much money. I think a $500 budget for the materials and outside work would be do-able. You may be able to beat that if you can scrounge up a suitable boiling tank for the rustblueing. I had a friend with a fabrication shop build mine. But other than the tank, there's not much you can save on.