we apparently have two electrical boxes in our home, one of which has screw-in (edison t type? ) fuses, and has been tripping about once a month.
we can see that the smart thing to do is eliminate this box altogether and upgrade the more modern main circuit breaker and electrical box to handle the circuits from both boxes. but that's not in the budget yet.
my husband, mr. frugal scientist, got out his scientific equipment and determined the resistance was too high, and the fuse in question is getting too hot. and to delay the repair he basically shut off the power and took this old electrical fuse socket apart and cleaned it very thoroughly, assuming the resistance problem was more likely to be in the fuse box than the wire. he triumphantly said resistance had dropped, and proclaimed himself right, but when he went to screw it all back together, he totally destroyed some kind of thermally insulating (asbestos?) washer behind the fuse.
we don't even know what this washer is called and I don't think they sell it anymore. i also don't know if they sell porcelain or polymer replacements or where to look. In the absence of an available commercial part, mr frugal scientist is looking up thermal ratings and insisting that he can use a printed circuit board or something, just cut it into shape and squish it in there and it would be safe.

He's a smart guy but he's no electrician and I have the heebee jeebees about this.
I wanted your opinions: is there something commercially available as a washer we should be using? Is his proposed solution safe or should I insist we get rid of the whole box right now, even if paying it off takes a while?
Thanks