Thank you guys! About the finish, the idea is to grain fill with a dark colour as on the test piece. A subtle burst effect could be created by sanding the grain filler down more cleanly in the middle than at the edges of the guitar.

The hardware store over here did not sell special grain filler, so I used white wood filler mixed with the black stain powder. It seems to work okay, when diluted with some water. But then again, I have never used grain filler so is it recommended to go buy that from a specialist shop instead?

The teak oil seems to bring out a bit of a yellowish warm tone in the stain, which I like. I have been reading on the forum quite a bit and noticed many builders choose a Tru-oil as their finish. In what way is Tru-oil different than other types of oil used for furniture?

Do people use an oil finish mostly because spray-painting is difficult to get perfectly right, or is it mostly for aesthetic reasons?

I have used hardwax oil for wooden floors on my drums, creating a very durable matte finish. I assume tru-oil is not entirely comparable with this type of hardwax?