Provisional

Here's the symbol it was derived from, as found in Symbols, Signs and Signets by Ernst Lehrer (Dover Press).

Here's an alternate arrangement of letters F, which I don't like so much as the first, but it's part of looking for a SMALL (i.e., low kilobytage) image. The background color, cyan, was just an experimental shade to make sure all letters F were adequately contrasty. It would probably work better if the bg shade were ivory.

So off I go to work with animal drawings, monkeys and ferrets.