Mark 2, that is very promising. If you try shooting with the flip-up sight at the bottom, the group should come down quite a lot - and be a bit tighter too, although what you have is already better than I could manage looking through the battle sight aperture.
As to stock and furniture, if I managed to find a complete Eddystone set for 60 euros from a scrapped rifle, you should be able to find something for a lot less than 200 dollars if you are patient and ask in every gunshop you come across if they have any salvaged bits.
Patrick