Lights went out while going over Tobin Bridge

So let's do some math.

P=V x I

Power in watts equals volts times current in amps.

Move it around a little, law of equality, dividing both sides of the equation by V for volts comes out with:

P/V=I or power divided by volts equals current.

60 watts/12 volts = 5 amps. Times 2 for both headlights is 10 amps.

If all power for the lights goes through one fuse, you're right at the limit. If parking lights are also on there(I'll wager they are) you're clearly over the 20 amp fuse capacity. I'm thinking a 25 amp fuse is needed, as long as the wiring is at least 10 gauge. If it's 12 gauge, 20 amps is the limit.

My brake lights are on a separate fuse. My high beams and low beams(with parking lights) are on SEPARATE fuses. That is how Vintage Motorcars wires them up.

Marc could conceivably leave it all alone if he switched the headlights to LED bulbs.

There is still the possibility that something is loose and shorting out.

Great analysis, Danny. I agree. I'm also wondering if the mysterious empty yellow fuse holder went with a long-gone radio.

I had an orphan like that when I bought my car. Turned out someone had run a separate fused wire to my fuel pump.
But obviously if that fuse went out, the car wouldn’t run.

I assume the PO did it when he replaced the original 1600 (that probably had a mechanical pump) with the CB engine that’s in it now.