I finished a hard maple stock recently. I used home made AF for the stain. Steel wool and nitric acid, ...about 20% acid. Over that I used Ace Hardware BLO. I laid on a sloppy coat and took off the excess with a rag. I put on a second light coat a couple days later. It came out fine. Maple is very dense and does not absorb as much as walnut. No filling is necessary. No sticky and it has a sheen. Good enough, I wanted an old time look, not a piano mile deep perfect gloss finish.
Lots of old guns were done in varnish. You can certainly float on a coat of goood old Mclosky varnish with a sabel brush.
IMHO lots of folks over complicate finishing wood. 90% of it is about proper prep. On walnut fill the grain first! IF you want a mile deep shiny finish fill the wood and use spray lacquer or varnish. You can use catalized urea formaldehyde, AKA. Fuller-Plast but that is not appropriate on a ML. That stuff is how Remington and Weatherby do it. It is noxious and toxic, forget it. For a dull finish, fill if needed and use BLO or tung oil. Tru oil does not build well and is not suited to the shiny piano look. Used sparigly, like real oil, it leaves too much shine for me. Haven't touch the stuff in 20 years.
It is fun, or used to be anyway, to lovenly run a zillion coats of oil on the wood. It is not really necessary and indicates you did not fill the grain. Oh, PS: fill the grain with sanding dust made with 320 grit paper and diluted spar varnish. A close second is commercial paste filler that is tinted dark.