I've never used boiled linseed oil simply because so many highly respected stock making experts have advised that it is a poor choice. Comments like "better than nothing, but not much" seem about par. My 16 ga. NID with original finish has a tiny bit of cracking and peeling near the buttplate, and enough gloss and surface build that I would guess it is an aged varnish or lacquer.
Unfortunately, the guy who would probably give you the most definitive answer, Walt Snyder, has not posted here for a while. Someone pissed him off with their comments recently, and I for one wish he would reconsider his decision because few, if any, have his level of Ithaca knowledge.
Motion: C'mon back Walt Snyder! Will anyone second that?
