For the blinkers/brake lights/etc., I would check your hazard light switch. If it's anything like my 71, a bad switch there (or an incorrectly wired one) will take all of those out. They all run through that switch so that they can come on when you turn on your hazard flashers.
For the headlights, I had a similar problem. First, go back to the wiring where they connect to the combo switch on the steering column. I would bet that you simply have two of them crossed, assuming they were working previously. If not, try turning them on and seeing if you have any current downstream from the switch. You can do it right at the headlight socket if you want, but if you're reading some voltage, but not a full 12+, then I would suggest cleaning the contacts on your headlight switch. It's pretty easy, but if those contacts are corroded (mine were) and you're not getting a full 12+ (around 12.3-12.4 with the engine off) then I would bet that's where your problem is.
FInally, I would strongly suggest the fuse box upgrade that MSA sells. It's an extremely worthwhile investment, and once you get everything sorted out, it'll give you gerat peace of mind knowing you're not running the older fuse box that tends to melt...at least if it's like the one that was on my 71.