Hi John, You can get linseed oil from any hardware store. There's two types, boiled and plain. I have used both, I didn't notice any plus's or minus's. As for tung oil, which I haven't used, has the effect of diffusing light, basically an oil finish will give you finish that has a depth appearence,and a wet appearance. Where as the tung oil will give you a more or less semi-gloss to a flat appearence. The linseed finish is very forgiving with dents, they will not "whiten" when dented as a varnish will, however the oil finish is not water proof, at best it's water resistant. I beleive the tung oil has better water resistant properties, but I think it will whiten with the dents.The tung oil also can be purchased at a local hardware store.Now as for the Laurel Mtn. products, they have stains, sealers, finishes,and barrel browning agents, you can acquire them through MUZZLELOADERS BUILDERS SUPPLY 479-292-8866, 9am-5pm central... they are in Ark.
Hope I helped...........George F.