Bevo, considering the age of your radiios, even though they are in like new condition, I'd recommend replacement with new equipment. Even though your radios have little or no use on them, they are still OLD radios and some components have aged even without use.
There are so many excellent, low to mid priced radios available today and most of these will have features not dreamed of when your 783 was new. Look around and choose one with the features you like, then buy the next model up just to be sure you really buy enough radio! Trust me on that last statement!
I feel your pain as I have several older radios that had little use before 2.4 came along. i bit the bullet and bought new and am very glad I did. The old radios just sit in the radio cabinet and remind me of what once was ... then I pick up the new radios and go fly.