It would seem that many rough old doubles have come out this way from India in the past few years.
Many of them might at first have the looks of a diamond in the rough, from time to time though, they're more akin to a boot in cow manure.

With a double rifle, you really need to be careful about what you're getting into, gererations of substandard gunsmithing, rough handling, and humid climate along with the possibility of corrosion from cordite and/or black powder residue can completely screw a double rifle beyond a chance at getting well enough to run again without spending money well beyond what it'd cost to get one that was fit and running right in the first place.

You really do need to know what you're looking at.
You really do need to know what to look for.
Furthurmore, you need to get the thing out and shoot it to see if you're ever going to get it to perform as a double rifle should.

There are a couple of threads going around here currently of used double rifle purchaces gone to hell.
Take a look around and learn from the experience of these folks before you spend any of your money on a used double rifle. You'll stand the chance to save (or loose) a lot of money as well as time and frustration.

--Tinker