RC10 CE 6 Gear Pinion??

[Albertini]

I'm trying to resist the temptation of running my RC10 and let it just sit on the shelf as it has for the last year but I think i'm going to give in and give it a blast

The first hurdle though (apart from tyres) is the motor pinion. The one that came with it is normal (b4) pitch(?) and dosen't match the 6 gear's spur. What do I need ?

I'm not likely to run anything more than a 19t so not sure where I should start gearing it from either? Any help would be much appreciated?

Thanks