The Trident 1 had a M.88 cruise with a Vmo of 385 We used to demonstrate them during Base Flying to M.93 as required by the 1179 form. I have seen them at M.97 with no mach buffet until some G pulled and then only very slight. I remember a time when we were hasseled by a pair of Spanish F86s after departing from Gibralter and managed to pull away from them at m.9+