I've got an old lever gun that lives in a mud bucket to contain the leaks, no idea of the brand. I don't use it much either. I did grease the new and rebuilt parking brake stuff last year but won't do it again for several years of summer only use. Same with the front end, u-joints, water pump etc. Grease them once sparingly and don't over do it and blow the seals. Blown out seals from over greasing can cause component failure; no seal no grease. Actually many components, u-joints for example, are packed with grease on assembly and don't need the gun at all, even if they have grease fittings. Finally, modern synthetic greases are much better than the period grease. If the seals are intact, the grease stays for a very long time. My opinion only of course based on not much but as they say, has worked for me.
Tom