I don't have a II but I have a couple IIx systems and a spare IIx motherboard and all needed the aluminum can capacitors replaced. Other then that the big box II's seems reliable (also have a pair of IIfx systems). Build quality is about as good as a 68k mac gets (they were the pro machines of their day).
Those aluminum capacitors have a use life in the thousands of hours and since all those systems are very old they probably all need serviced by now.
Replacing the pram batteries on a II should be easy enough, new ones can be found on ebay cheap (just a little simple soldering needed). If you cannot solder find somebody who can and get them both fixed at the same time. There are not that many capacitors to replace (just do the leaky metal can ones). I think 20 minutes a board is all you need.
Those aluminum capacitors have a use life in the thousands of hours and since all those systems are very old they probably all need serviced by now.
Replacing the pram batteries on a II should be easy enough, new ones can be found on ebay cheap (just a little simple soldering needed). If you cannot solder find somebody who can and get them both fixed at the same time. There are not that many capacitors to replace (just do the leaky metal can ones). I think 20 minutes a board is all you need.