I assume you are looking at them with the intent of buying one. Unless the price is good and your interest is as a plinker, I would have to say to forget the IJ and go with something of a more modern design that has a "home." They have some collector interest, but only in new condition. Average condition guns sell for $100-150, with few takers.
The main weak point of that revolver is its antiquated (1880's) design. The trigger pull is hard and usually rough, and can't be improved significantly. (The trigger, sear and hammer are case hardened, and stoning will ruin them.) The real weakness, though, is in the hand. Any wear on the hand will result in failure of the cylinder to time up properly, plus the cylinder ratchet is not well designed or cut very deep, so it wears also, with the same result.
Another point, if you have any ideas about disassembling an IJ (or any other guns of that era), forget them. Unless you have skill and experience, the parts will go into a box or paper bag to be worked on "someday." Most gunsmiths won't work on them because they are such a PITA and they would have to charge more than the gun is worth.
If you want a .22 revolver, look at the Ruger Single Six or try to find a decent used S&W Kit Gun or K-38. Any of those would give you a lifetime of service with no problems. As to .22 semi-autos, there are a whole bunch of good ones from Ruger, Browning, Walther, and others.
Jim