[Scorch]

It all depends on how you want to do it:
* TruOil builds up, but it is just an oil finish, and it scratches fairly easily once it is set up.
* Yes, you can use Permalyn. Permalyn is a polyurethane oil that will build up very fast and gives a clear high-gloss finish. Scratches pretty easily, but not as easily as TruOil.
* You can also go to any one of the polyurethane finishes available, like Varathane or MinWax floor finish or poly spar varnish. Fairly tough, good wear resistance.
* If you want something harder than a poly finish, you can get AcraWood from Brownells. It is a spray-on solvent-based epoxy wood finish. Very hard finish, and it comes in gloss or satin.
* If all else seems too mundane, you can have DuPont Imron sprayed onto your wood by a knowledgeable painter. That is the same finish as the original Remington 700 BDL rifles of the 1960s and 1970s. It is as tough as nails.
* If you feel adventurous, you can find someone who sprays celluloid. That is the finish used on Fender Stratocaster guitars from the 1950s until the 1980s. Definitely high gloss, clear and hard. High VOC, so most people have abandoned it, but there are still a few people spraying it.