Ive talked with a few dealers, and here are some recommendations on what to do with "new" aquisitions.
Firstly, its good to see what youre working with, before you determine what steps should be taken next.
Starting with the blade, you can remove dirt, oil, and grime on the blade with a good cleaning with acetone. Also really helps if there is any cosmoline on the blade.
Next, light cleaning of wood parts with warm soapy water. Murphy's will work, but be careful cause the stuff can strip certain finishes. I know a few dealers use just plain old dish soap. However, there is special anti-fungal soap, that is super gentle, and used by museums. But from what my dealer friends tell me, its real similar to dish soap, and the results arent really that much better, unless there is a fungus/mold problem. The key is gentle cleaning, dont soak the wood, especially since excess moisture can lead to mold/fungus/rot. If youre really worried, a warm soapy wash-cloth, and light tamping will allow you to go slow. Though, you can just go ahead and wash away, normally if you are confident.
Now, after these initial cleaning, its time to ascertain what further work needs to be done. Live rust on the blade would be a first priority. That can be taken care of with gentle rubbing with #0000 steel wool. The reason for using #0000 steel wool, is that hopefully the fine wool will break apart before scratching the patina, but is strong enough to take off live rust. If the rust is stubborn, soaking in a penetrating oil like WD-40 will help loosen it (ballistol will work, probably real good, but for just loosening the rust its kinda over-kill), for another session of wooling. For stiffer rust you can use a penny, again the softer vs harder material logic. Some people have been known to use antler. If youve done this alot, you can actaully use something harder, like a dental pick, but I do not recommend it unless youre used to doing this stuff. Just remember to take things slowly, and when in doubt, dont do anything.
As for polishing out scratches, without seeing how deep the scratches are, and where they are, it is not something I would recommend. Firstly, you will remove patina, and secondly, it can cause a blotchy finish (eg. polish spots vs non). Removal of live rust can go a long way of evening, out the finish, but often Ive noticed that what appear's to be scratches to the patina, were in fact grind marks from when the blade was last sharpened. Realistically, there aint a real way to re-polish a blade, and leave patina intact. In the end you can only compromise with how much patina you remove, and how much you even out the finish. But realistically, scratches have a way of being much deeper than they appear, and without going through a full polish, trying to polish them out can be more damage than good. But then its you khukri.
Now for the wood, Ive found #0000 steel wool is real good at further removing dirt/muck that couldnt be removed in previous washing, without damaging finish/patina. Just be careful, and take thing as they come. If the finish isnt too bad, a good furniture polish is good for up-keep. However, Ive re-finished quite a few neglected items, with a special oil blend, but I only recommend that if there are serious cracks/dry-rot.
Hope that helps some.