A few more distributors came to mind that don't have a section of their own, United Artists, I have, or had a catalogue of silent digests, it consisted of a number of Warner Bros films, Edward G. Robinson, and Errol Flynn, then there was Paramount, I only had one of theirs, a 200ft of 'Samson & Delilah'
Some of the British companies issued theirs in relatively plain boxes, so once you have seen one cover you have seen all, Powell Films, and P.M. Films are two.