Yours has recently been rebuilt so the gearbox and motor should be fine for a while yet. Greasing the gearbox is a dismantling job that cannot be done with the motor/gearbox unit in situ ;
Motor assembly
http://c5alive.co.uk/forum/index.php?topic=368.0Gearbox removal
http://c5alive.co.uk/forum/index.php?topic=1217.0Pedal crank, steering and front fork bearings were also recently re-greased on yours so should also be fine for quite a while yet , again dismantling is the only way to access them;
http://c5alive.co.uk/forum/index.php?topic=239.0Front wheel bearings are standard bicycle components so no worries there, rear axle bearings are another matter ;
http://c5alive.co.uk/forum/index.php?topic=342.0 I'd expect the first areas to show wear and tear will be the usual consumables such as tyres, tubes, brake blocks/shoes ,brake cables, chain ,drive belt and chain tensioner clip. The rate of wear will depend on usage
Short answer is - keep the chain oiled nicely