As a guy who has done both multiple Boyd's Stocks (& others)
and Antique Furniture Restoration, my suggestion would be...
CITRISTRIP, at every Lowe's & Home Depot.
http://www.citristrip.com/product/citristrip-gel
In fact, I just got another can for a small project...
a Schecter 5-string Bass that the finish is pretty much gone...
dude either played a LOT, or never wiped it down after playing...
Oh, yeah, make sure it's a WARM Garage...
turn on a heater and get the place nice & cozy
so the gel will do its thing faster...
because in wintertime, everything of that nature slows down...
and a little goes a long ways...
Removes pretty much everything...paint or varnish or laquers...
Citrus-based, but you still need to wear gloves,
because it'll do bad things to your unprotected skin...
This Marlin 60 had a standard Mar-shield coat,
which was a heavy polyshades brown, almost a paint,
with a couple coats of Polyurethane...which looked nice & uniform,
to Marlin's Standards. however, as evidenced by the finished product,
there was quite often some mighty nice wood underneath...
once you Citristripped it off