Sounds like the main fuse(s) could be original from the 1960's, or could be one-time fuses instead of time-delay (FRN/S) type. Fuses don't last forever, sometimes they just blow due to age. I still wouldn't go poking around in that panel though. If the fuse(s) blew due to excessive heat from a loose clip, it could have caused the insulating plastic (bakelite) parts to weaken. Any stress placed upon them could result in breakdown and major arc flash exposure.
I tend to think that my life is worth more than the cost of a service call. I hope that you'll consider biting the bullet and paying for one instead of the possibility of biting a feeding tube for the rest of your life (if you are lucky).
Sorry to be so blunt, but this could be a truly dirty job and if there's any doubt, you should consult a pro. I do have one question though: If you've been in this training, haven't you met anyone who might be able to connect you with a licensed pro who might be able to help you out? If you don't have the money, maybe they will help you out and possibly hire you at the same time. Hey, anything is worth a try. Seriously, please don't mess with this on your own.
