camera lenses are not gas filled
so a shop that repairs camera lenses wont have the right equipment to do a nitrogen purge on the scope body while re-assembling it.
Most camera lenses are not gas filled. There are specialty lenses that are gas filled. The ability of a shop to gas fill a lens (other than a manufacturer) would depend on how much call they get for it. I would guess that an independent shop would suggest sending such a lens to the manufacturer.
AFAIK Argus (the US camera firm) made M49 scopes and a civilian version with a black crinkle finish civilian version. If there is water inside the scope then it never was gas filled or the scope was damaged and lost the gas long ago. I don't know when they started filling scopes with inert gas but the M59 is a WWII era scope. If gas filling wasn't common then I doubt your scope was gas filled to begin with. I doubt it was gas filled to start with.
Manufacturers generally won't offer to fix anything they didn't make for obvious reasons. They often won't fix their own stuff if its 50-60 years old as they don't have parts anymore.
We can sit and speculate if the scope was originally gas filled and eventually get an answer. The moisture in your scope can be formuing fungi and mold that will damage the coatings on the lenses in the mean time.
If I wanted to save scope in similar condition I'd take it to someone who could take it apart, dry it out, and reassemble it properly. I'd worry about getting it refilled with gas later (if it ever was filled with gas).
Taking it apart and doing it yourself is not an option unless you know how realign the lenses properly and have the equipment to do so.
