For anyone interested: I went to the Benelli Bauer website and there are two parts drawings for 750 SEI forks. The earlier version (drawing 16) is a more traditional style fork. Very similar to my Honda cb750K bike’s. Drawing 16A shows the later “Series 2” forks that are fitted to my ‘77. I believe they are Marzocchi. In addition to the usual spring and sliding tube, there is a sealed, cartridge style “shock absorber” in the top half . Today I took it apart and laid out all the parts.
I have a new pair of fork lowers, so I am ordering a bunch of parts, seals, and a pair of the internal shocks. They appear to be designed to control fork rebound. When finished, I’ll have a nice, fresh set of forks for the Spring. Anyone interested in photos of the internals, just let me know and I’ll post as I go along with the build.