I would not mess with the outside, it looks good. The factory finish is likely to be poly but I don't think you can tell by looking at it. If you are worried it is not moisture resistant you can put a drop of water on it and see what happens. If it is sealed, the water will run off. If it does not run off and especially if the wood darkens in the area of the drop, it is not sealed and probably should be. Once a finish has dried, you can generally put another finish over it but it is best to try it first in an area where a boo boo would not be a big deal. I would also check the inletting. If it is sealed, no need to do more. If not, then I would seal it.
I make wood furniture and I have used oil and water based polyurethane and water based lacquer. They all retard moisture absorption (seal the wood). Oil based poly gives the wood an amber tint. Spray on finishes are very thin, about like wipe on. Wipe on is just oil based poly thinned out. It would be easy to use to seal the inletting if required. Linseed oil and tung oil do not seal the wood. Danish oil is linseed or tung oil with some varnish added. It will seal with enough coats. Most recently I have been using Osmo, a "hard wax oil". It is pricey but easy to apply and seals the wood. I'm not sure what is in tru oil although I have used it. I think it is like danish oil - has some sealing capability but less than a poly or varnish.
In short, you shouldn't need to do anything but checking to see that the inside and outside are sealed would be a good idea. If you need to seal the inside, I would probably use wipe on poly just because it is easy to apply. On the outside, it depends on what you want it to look like. But if it is sealed, I would not apply additional finish.
