"with regards to the age of the unit, is that a potential issue as to it's potential life expectancy?"
Yes, and no. Expect that some parts are faulty or likely to fail soon. But then you have something to study and fix. Studying and fixing a scope will give you lots of experience. If you fix the one component that is faulty, the life expectancy of the scope is expanded, of course. As long as you can replace the faulty parts, it will last forever... Usually it is just a troublesome solder joint or a dirt cheap resistor or a easily replacable transistor that fails. Sometimes it costs a little more i.e. if a $50 nuvistor is blown.
Search the internet, and primarily buy stuff that is widely known with lots of info, like schematics, user manuals, calibration manuals, etc.
You should probably save some money for some more recent gear...