hi Andy
from the pics you sent it wont work on your machine as it appears to be Ali base worktop , no magnetization need to be a steel base worktop to be able to hold , but also from the pics , and you probably don't want to hear this , there is no way i would machine a piece of timber like that .
I learnt my lesson yrs ago , i use a rubber suction mate and use a portable hand held router for most things ,both hand on the router and not as you have just found out to your cost , sorry .
ax minster system works like :- place timber up against the fence , but your fence has no cut out to house router bit , and then timber next to fence , next place feather board against timber with enough pressure to slightly bend feathers and turn locking knobs to lower magnet to steel bed when in contact with steel bed it locks into imposition,to move it you have to apply a great deal of force . hc