I found the diagram a bit hard to fathom as it was shown, so I drew it out with all the wires added, then traced it out, using different colours for each switch combination - and IT WORKS !
You didn't label the switches, so I made the assumptions that: the lower left switch is footswitch 1 (for FX1), the lower right switch is footswitch 2 (for FX2) and the top one is the change-over toggle - and, as it all worked out, it seems my assumptions were correct.
Blue Tubes, you are a freaking GENIUS !
I've only been able to do a similar switch-over by using a 4-pole toggle switch.
Now I've got a whole spare pole to play with !
