
I found one more, as Writer Paul Bern, Raymond Griffith, Director Dimitri Buchowetzki and Ben Lyon clown around on the set of
Lily of the Dust, without Pola. Code 656-2/2.

Paramount stills like the one Derek posted that start the production number with an "L" were produced by Jesse Lasky's company. Here's one of Gloria Swanson in
The Affairs of Anatol (1921). Code L367X-288. I don't know what the X means.

And here's the "P" publicity portrait for Raymond Griffith. Code P613-37.

Paramount codes starting with an "F" are from the "Famous Players" studio. Here is Kate Bruce, William J. Butler, Irene Fenwick, and Owen Moore in
A Girl Like That (1917). Code F137-85.

Adding to the confusion, here's Kate Bruce, Irene Fenwick and William J. Butler in apparently the same film, but it has a different production number and has no "F"! Code 139-4.