There are about 14 – 16 cage nuts used in the L-5. These allow machine screws to be used without cutting into the fabric / wood to hold a wrench on a nut. Yesteryear Aviation has them. They are a Stearman restoration and parts company.
They are used on the horizontal tail, wings, and front door. In the Parts Manual, go to the Numerical Parts Listing and search for W1481032. In my 1949 IPS, shows figures 5,14, and 3. Manufacturer was Boots.
I followed Charles lead and recently recieved 20 from Yesteryear Aviation, many thanks for the heads up Charles, I found Dave Groh very helpful. He is not so good with online requests but excellent and responds quickly to phone calls. Dave has plenty in stock if you are still looking but they are expensive (USD$3 each plus any shipping). Glad i got some before the latest exchange rate fiasco.