My reputation has already reached the shores of NZ?! 't is true that I am a wine importer, may I ask how you know?
As to GP reassembly, taking out the barrel is a good step. My 'normal' method is as follows.
1. Insert breechblock and extractor (my breechblock has very tight headspacing, so I need to put in the extractor at the same time), and make sure the blockis in the closed position.
2. With the action upside down, drop in the sear lever
3. Now - this is the tricky bit - drop in lever + trigger guard, and insert the main pivot pin (the one through the lever/sear lever) with all holes aligned, if need be use a slave pin to line all components up, and make sure that the rifle is uncocked for the next step
4. (you will need 3 hands) while pulling the trigger, push home the front of the trigger guard against spring pressure. While holding the trigger guard against the receiver, line up the extractor and insert the extractor screw - and it is back together....
5. Insert the safety, taking care not to lose the spring + plunger - the rifle needs to be cocked to do this...
6. Take a cool bottle of wine out of the fridge (maybe some NZ sauvingon blanc??), sit in a lazy chair, and congratulate yourself on a difficult job well done
7. Sip the glass of wine
Of course, 6 and 7 are optional, but well-deserved after finishing that tough job...