I second the CPF suggestion. You can DiY any number of ways with or without boosting the voltage up for green-blue-white LEDs. A single red-orange-yellow LED with a resistor in series is all it takes for a simple conversion. Or you may purchase a drop-in conversion - some use a bulb form factor (same base and general form as the bulb); others are a bit different. The ready-made conversions are not cheap. I've converted two [email]M@glight[/email] D-Cells to Luxeon Stars, which are drop-ins - awesome. And two [email]MiniM@g[/email] 2-AA cells to LED - one Luxeon Star and one 3-LED (4 counting the red voltage indicator LED, also pretty much drop-ins. And one Solitare to LED DiY. I would not bother with purchasing an incadescent flashlight for the purpose of converting it to LED - just buy an LED torch to begin with. But to take an oldie like yours and convert it is a GREAT idea IMHO. You will not have any trouble getting specific info over at CPF.

Have fun!

Tom