My daughter picked up a 1930 vintage Savage 28 pump shotgun. Sometime along its life the stock was shelaqed. I've scraped the shelaq off, steamed out most of the dents and applied a couple coats of boiled linseed oil. I don't want to change the character of the stock, I've not sanded out the gouges. But BLO doesn't moisture proof wood very well. What other finishes might have been used during that period?

There were other oil finishes used, like Tung oil.
Most seemed to use Linseed oil or Tung oil with each maker using their own formula of driers added.

To give a 30's type "in the wood" oil type finish that IS waterproof as much as it's possible for wood to be, I use Minwax Antique Oil Finish.
This is some sort of modern oil type that's the toughest and most water proof oil finish I've ever used.
Few common solvents I've ever used affect it, and the grain will NOT raise on a hot, damp day.
Once dried even lacquer thinner doesn't seem to affect it.

The way I used it was to apply a thin coat and let it dry, use 0000 steel wool to polish it off the surface and repeat until the grain is totally full.
As often with any wood finish, the first coat never really dries, it stays sticky.  As succeeding coats are applied it dries faster and harder.
This usually takes 4 to 6 applications to totally seal the grain and leave none exposed.

After the final coat is dried, you can leave it on the surface, or steel wool it off, let it age a week, then buff with a clean piece of burlap.
This gives a true 1930's "egg shell" luster finish and it's all IN the wood.
If needed, you can repair damage by simply applying another coat or two.

Here's my 1950 Marlin 39-A, which originally had the American "Red" oil finish used by most pre-war gun makers.  There's no surface finish on it......

Thank you. I knew someone would have an answer.

Minwax has had the Antique Oil Finish for wood a long time. I have a can with the red and white logo that I believe came out of my wife's grandparents house a couple decades ago. I got the cap off and it's still clear and going on now. I'll show pics when I'm done.

Let us know how it comes out.

Again, the first coat or two will never really dry, just let it sit a day or two then steel wool it off and continue.
The more the grain gets filled the faster it dries.

Minwax Oil Finish is as tough as chicken lips.
I always kept a small lidded container on my bench filled with lacquer thinner to clean small parts.
I spilled a drop of Minwax in the container 25 years ago.....and it's still there.

With most all oil type finishes if I went to the range on a hot summer day the moisture from my face would raise the grain on the cheek piece.
This happened with Linseed oil, Tung oil, BLO, George Brothers Linspeed oil, and others.  
NEVER with the Minwax.
It's also a harder finish then the others.

A pain to do, but like the old gunmaker oil finishes, it's a once in a life time job.  Thereafter, you can just over haul it by applying another coat or two.

Attached File
@dfariswheel
Here is the finished gun. Stock matches forearm real well.

Very nice looking job.

Hard to do, but a once in a life time job.

This is 100% the correct answer. Antique oil is like cheating for bringing back an old gun.

Also try steaming out the stock before you sand it. You won't take the gouges out but you'll raise some of the dents.

ETA: Beat like a rented mule. That gun looks absolutely outstanding.