Just ordered myself one of these, did you manage to adapt the hop arm to fit a nub or just ran it with the prommy rubber and the standard plastic hop arm/built in nub? Got myself a purple rubber and a barrel to put in it when it arrives so was just wondering.
Also will ask, did you stick with a 7.4V or attempt the 11.1V, as I've seen a lot just saying use 7.4 for UK limits.
Cheers,