Sorry, Stereo carts were used generally on mono systems with the channels combined. 99% of purely mono cartridges then had NO vertical compliance whatsover. Therefore, damaged Stereo LP discs very quickly. And they tracked often over 6 grams. There's two vintage mono cartridges I know of which could safely play Stereo LP discs without damage, the Weathers FM integrated tonearm/cartridge system with FM demodulator box (manual turntables only) and the Shure M1 Studio Dynetic integrated tonearm/magnetic cartridge system (again manual turntables only). Both of these tracked at extremely light tracking forces then (Weathers at 1 gram) and (Shure at 2 grams). This held true until Denon released the DL-102 mono HOMC cartridge in 1963. (which was designed for the Japanese NHK Radio to safely play Stereo discs in mono, and mono discs equally well).