Willie, have you taken a close look at the headlamp? Moisture can ruin the reflective surface over time. The units can be disassembled for repair, although I'm not sure how much luck you'd have finding replacement parts. Reflectors certainly can be resilvered by shops that specialize in that process.

Otherwise, I wonder about the condition of your wiring and switch, and even system voltage (alternator). A set of euro lights should blow away any sealed-beam setup you can install, bar none. I'd use a multimeter to test voltage at the bulb socket and especially resistance on the ground wires (should be close to zero ohms).

Whatever you do, resist the temptation to install overwattage (80/100) bulbs without rerouting the power source through relays. The excess current through dicey circuitry could burn it out -- in fact, I wonder if a previous owner might have subjected the lighting system to that kind of abuse.

One possible fix, assuming your alternator is producing adequate juice, is to install an aftermarket relayed wiring harness. You'll get plenty of lighting power from that upgrade, along with the ability to upgrade to high-watt bulbs if you like. You'll probably find that you don't need them, though.

HTH
Russ M