Remove the centre bolt and fit a 3/8" bolt of appropriate length, the 3/8" bolt should have a 1/8" hole drilled through the side just above the slotted bracket of the tripod, then as you fit the 3/8" bolt, place a washer onto the bolt above the slotted bracket and pass a brass pin through the 1/8" hole you drilled.
That stops the bolt falling out when not attached to a mount.....
Me to Matt , almost exactly what I done to so here is mine holding my 150mm Saxon in NZ , great tripods .
