Charlie 'da Tuna tuned my Silver Shadow 1000 in '08... it is still the most accurate, sweetest-shooting rifle I've ever had the pleasure of firing... it was a mess before he got hold of it, though... it definitely needs to be tuned and triggered to put the fun in it!
Just get yourself Charlie's trigger. It shouldn't be too much shipping to Guam. The new trigger will make all the difference in the world. I would also get a rube of RIG, put a small dab into a soft cloth, work it around and then wipe down your metal parts after each use. Also a can of Birchwood Casey Barricade. A little bit on a cleaning patch run over the metal before wiping with RIG and then store in a silicone impregnated gun sock. That's about the best protection you can get and you will need it in that humidity. They still have those egg-sized rain drops? Man, I can still remember being topside for muster (was on a sub in Apra Harbor), watching that morning squall line approaching and wondering if we would finish in time to haul buns back down the hatch, LOL! Dampness you can cut with a knife.