The cork sheet that I've seen is actually made from reconstituted cork - cork granules in a binder matrix - and is a good bit 'stiffer' than plain cork sheet would be.
The bag exchange system was still in use in GB until 1971. I saw it done a few times in the mid-'6os - very violent - do not post antique crystal decanters by this method....
That's the 'collect and drop' model. The cams to lay in the track can be a bit finnicky - and the bags are difficult to obtain, though you could make something suitable.
The brushes and the commutator in the pancake motor aren't always the best - and can dig in a bit where the brushes run over the breaks between the copper segments. The flywheel-effect of the rotor at speed helps overcome this, but with low-speed running, it will often stall. A bit of rounding off of the copper edges can help. This problem gets worse as the carbon brushes get shorter.....
There's surprisingly little news attention to this story - http://www.itv.com/news/update/2014-11-08/police-investigate-reckless-attempt-to-derail-a-train/ - seems to have been rather a near thing.....
Indeed, and particularly useful for 12V 'grain of wheat' bulbs - I usually run them at around 8V - a nicer light and they last for ever - two in series off a 16V supply...
Indeed, and I would have been reluctant to post this, if it hadn't come through Irish Rail itself.
I'm sure that Belmond know what they're doing, far better than I do, but it does seem very ambitious on such a small network.