Tool box knob replacement
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
Like side cover knobs, the special tool box securing screws seem to disappear. You may be able to find a used pair of screws on ebay, but they are getting rare and more expensive. You could also create a functional - and less attractive - set yourself using a long 6 mm bolt.
A better solution is to contact Mark Etheridge of Moto Guzzi Classics. He sells newly made replacements that appear identical the originals.