I tried using Tung Oil as the finish on the last couple guitars I've built, and I gotta tell you, I think it is great.
I really like the way it flows on the wood surfaces, and the semi-gloss luster of it is nice. I like poly for the durability of it, but the oil is a better choice for me.
Tung Oil can be applied with a soft cloth, but I prefer to use small brush to carefully stroke it smoothly onto the surface. Within thirty minutes, it is ready for a light sanding with 1000 grit wet/dry sandpaper, buffing with a lint-free cloth, and after drying overnight, it leaves a beautiful finish. If the finish starts to lose its luster after a time, a light coat of oil brings it back to life.
It's worth a try. Let me know what you think.