I used LED for dash board - think there are some pictures on my resto thread. You can't use a LED for the battery/alternator lamp though. Not sure on headlights think peeps say something about HID or H4 can't remember which now but there's been some threads about these recently.
For the headlights, I replaced the candles-in-jam-jars with some crystal clear Golf mk1 headlights (they are the same fitment as Late Bay) with some Philips Blue Vision H4 bulbs and they made a big difference. On the left is the new headlight, on the right is the old one:
I would keep it as it is but clean up all the connections you will be amazed if you do use leds dont use them on the alt light unless you fit a resistor
Depends on what headlamp bowls you have. If the split type with a separate bowl and lenses look at my how to as a cheap option of repair. Mine worked a treat and are visible from the moon. Dipped, spotlights off High, spot lights on too. I buy my new head lamps from Holden vintage in Bromyard, dirt cheap and good quality lamps. Wipac 7"