True story ...
A friend sent his stock to a "master craftsman" in Texas to fix a split caused when he accidentally dropped the rifle on its butt while taking it out of the safe.
The repair guy took close to two years to return it!!
Apparently he had to wait for a tree to grow the get matching wood to make the repair!
If you decide to do this yourself, don't rush it. Get a really good surface after the complete sanding. Let each coat dry 100% (or more) before even touching it. Use very, very fine sandpaper (600-1200 grit or finer) to smooth between each coat.
If the coat isn't totally dry before sanding again, you'll likely ruin what you've done to that point and have to sand it down again to start over.
I've been doing some woodworking at home the past few years. Most who do this hate the finishing process because it's so tedious. Having said that, any woodworker, furniture manufacturer or wood finishing business should be able to do the job.
Man-hours are not cheap if you want a better-than-new finish. When all is said and done, you need to compare that cost with what a new, factory-finished stock from the rifle manufacturer or an aftermarket seller would cost. Even the DIY route will cost for materials, the oil, and your time. You also need a good place to work. Outside on the lanai while the trades are kicking up dust isn't ideal.