The only hardware you will need to source is the blade. You can use cut off nails or screws for the retaining pins. Paul has a free series on making a frame.
You can go to Lee Valley or Amazon and search on Bahco Bow saw or Buck saw replacement blades. Amazon sells several lengths.
The Bahco website has a store locator to buy their products if you want to buy local..
They have blades for green or dry wood.