Hi copper

You need to improve the electrical supply to the lights. Fitting expensive bulbs won't do much.

The dipped beam circuit at least does not have any relays. So the full current is required to flow through the whole circuit- fuse box, dash, column stalks and to the headlights. Lots of old connectors and probably burnt contacts on the stalks which will eventually fail.

There are several guides on the net. You can make or even buy mini looms to insert without cutting/modding the original wiring.

It works. Many including myself have done it.

Same technique can also be used to improve the wipers.