[Bindernut]

For starters, what are you cleaning up? Military, vintage commercial, etc? Is the original surface an oil finish or is it a varnish?
If you can, post up a picture of what you're working on.

With an oil finished stock, either old or new, I still tend to prefer Watco's Danish Oil finish. I use the natural color stuff for almost all of my gun woodwork. These are an oil-blend type finish...they've got some bioled linseed oil content plus some solvents and varnish parts to dry out the finish faster than pure boiled linseed oil.
Watco also makes a product called Teak Oil Finish which is the same oil-blend type finish as their Danish Oil except it contains more varnish than Danish Oil. Deft also makes a good one called Deftoil Marine Teakwood Finish which is very similar to Watco's Teak Oil Finish. These are geared more for use on wooden boats and outdoor wood furniture so that's why they have a bit more varnish in them. The higher varnish content makes for a better waterproofing product but it also will build up on the surface after several coats just like a straight varnish will. They make a good tough gunstock finish though.
Birchwood Casey's Tru-Oil falls into this type of category too.

I've also used Tung Oil finishes before too, but for some reason I just prefer using the Watco Danish or Teak finishes instead.
Formby's is probably the most common brand name you'll find but I've also used Deft brand Tung Oil and it works about the same.
These are also oil-blend finishes...meaning that in addition to the tung oil they also include a solvent/varnish component to make for faster drying time and a harder shell once the finish is dry.

You can also get pure tung oil, but it's like pure linseed oil or boiled linseed oil in that they take longer to cure out than any of the oil-blend finishes. These offer the least water resistance so they're not my favorite choice for gun wood...but on an old piece it is more authentic.
Klingspor is about the only brand I can think of at the moment that markets a pure tung oil finish but I'm sure there are more out there too.

When finished up applying the new oil (whatever type you choose), finish up with a coat of wax to seal the wood against water.
I know guys that also just use a coating of Pledge or Old English furniture polish too.
If you've got a nice clean finish, maybe all you need to do is to reseal the wood since Murphys strips off the wax seal pretty well.