Cab plumbing is simple enough - some (supplied) 0.8mm copper wire is fitted into 0.85mm holes drilled in the lost wax castings fitted in the cab. A few dots of superglue hold everything in place.
Drilling cast brass requires a nice sharp bit. The first one I tried wasn't man enough for the job but a change to a fresher tool allowed me to carry on even though I was using a pin vice rather than a power tool. Am I the only one who can't be bothered to plug something in for jobs like this?