Thank you everyone for posting. Certainly is some food for thought there.....on both sides of the equation. Tkamiya may have a really good point though, as cheap as most of our "old" flashes are, who cares? Get a another one and go down the road. That said, if I had just thrown down close to a 1,000 for a new Metz outfit (and I know many of you have them (me too, just used)), then I think I would be much more attentive and recharge the battery every 30 to 60 days and turn it on for a half hour and let it sit.
Since we will never know exactly what the quality level of the components of our old flashes, then I guess it's a roll of the dice. I do know that I need to grab the Metz though because I do believe they do recommend every 30 or 60 days you recharge your dry fit battery if you don't use the flash. Could this be another excuse to go take a picture?