These instruments are made primarily from recycled materials. Cigar boxes are obtained from smoke shops. Hubcaps are found at junk yards or yard sales. Pots and pans are usually obtained from flea markets and thrift stores.

Hinges and bolts that are used as tail pieces and bridges come from Habitat for Humanity Re-stores and usually are from demolished homes. Any nicks, dents, chips, stains or scratches are badges of honor.

The necks are hand carved from oak or poplar, the fingerboards are alder or yard sticks from local hardware stores and any defects, mistakes, gouges or drips are the sole responsibility of Rich and are included at no extra cost. 

I have found that the best resounding cigar boxes are those that have no paper labels to dampen the tone. Of course, these labels are a big part of the beauty of the boxes so I use both. Usually ukuleles are made with boxes without paper labels to get the best sound.

The 3 string Delta Blues Slide-neck guitars are meant to be played with a slide, usually copper, which is included. These instruments have no frets and their scale length is usually 24". They are tuned to an open chord, 1-5-1. Usually I use the 2nd 3rd and 4th electric guitar light strings and tune it to c-g-c. You can do what you want. There are no rules and if you go on the internet, there are many  tutorials on how to tune and play these instruments as well as their history.

Ukuleles are tenor sized with a scale length of 17" and are tuned CEGA

The banjos can be 4 string (tenor) or 5 string. The scale length of the banjos is usually around 24" or so.  Replacement strings should be the ball end type, not loop end.

There is a neat little battery powered amp available at Guitar Center called Honeytone.  It costs around $20.00 and does a fine job.