Googled Lyster "images." This link shows Lyster discs and master cylinder on Norton cafe: They look like what I recall from my days working for Lyster's US importer. The resevoir cap is a plain alloy disc held on with screws, not like the Honda's screw-on. The short 7/8" tube extending from the subframe back towards the Shocks is where the rear master was clamped.