Well, I had some time so did a quick scan of the Internet.
Javelins all use the up and away booster mount. At least by 1979 the Concord/etc. was using the angled stand-off mount. Early Hornets used the up and away mount, but didn't find enough to determine when the switch occurred.
My 70 Hornet has the bell-crank style; there's sweet-spot combinations of lever length, brake pedal hole position etc to allow for mods.