Learned the hard way
Three years ago I pulled the Univolt out and installed a new Intellipower in our Argosy. To save time and money, I elected to keep the existing fuse panel from 1972. I mean, everything worked and my local NAPA had the round glass fuses, so why get rid of something so simple?
Well two weeks ago we went on a family camping trip with our adult kids - three vintage trailers up in the woods at Lake Merwin in southern Washington. We were boondocking, so we were relying on battery power only. We set up camp, had dinner, sat around the campfire and enjoyed a beautiful evening. The next morning my wife was doing dishes and suddenly we lost all power. I immediately suspected a fuse, and sure enough, the main 30 amp battery fuse was toast. It hadn't blown, but showed signs of corrosion.
I drove to the nearest backwater store, and while they had plenty of new blade style automotive fuses and a few of the round glass ones, they didn't have the right one. So I drove another 12 or so miles to another store, a little closer to civilization, and again, plenty of blade fuses, a few round glass ones, but not the right one. By this time I'm already 16 miles away from camp, and only another 10 miles or so to Vancouver Washington, so I drove on to find a NAPA parts store. Guess what? They had a TON of blade fuses, and a whole lot of the round glass ones, but not the right one. So I drove to an O'Neil auto parts store - same story. Ace Hardware, same story.
After two more stops (seven in all) I gave up, bought some alligator clips and a 30 amp blade fuse, went back and McGivered it up.
So that's my cautionary tale. I've ordered a new, automotive type blade fuse block. I was lucky that I was able to figure out a work a round that worked. If we'd have really been out in the boonies, we wouldn't have been so lucky.
Sorry for the long post, but I thought my pain may be helpful to someone else thinking of making the same decision not to replace a 40 year old fuse block.