suspension mount hex size ansmann mad rat

[butters86]

Does anybody know what size hex key is required for the screws which mount the bottom of the suspension to the lower arms on the Ansmann Mad Rat?

I thought they where the same size as (For example) the gearbox cover but the suspension mounting require a slightly bigger key. The perfect fitting Allen key I brought with me to keighley (from Mansfield) spins round and I can't fit my new suspension.

I'm going to pop to the local model shop tomorrow to pick up the right sized key/driver so I thought it'd be worth asking on here first. If not I'll just take the car with me and try