Hi Denial, just caught up on this thread and really impressed with how things turned out.
Interesting to note that Tung Oil did not discolour the blue too much however there is still an aged yellowing around binding on the headstock that gives a hint as to what level of inherent colour it has. If Tru Oil was used I reckon we would be looking at a Peacock Green/Blue finish as it does have a much darker base tint.
For the truss rod cover I bought a couple of Rosewood ones on eBay for both my Explorers and they were as cheap as and also more shaped like a traditional Gibbo one. You can also buy custom engraved 3 ply black/white/black and plenty of Chinese copies with the usual Gibbo names already laser cut.
Cheers, Waz