They were part of FPE, then when FPE fell apart in the US they existed as FPE Canada, which eventually got out of the fuse business in around 1979, then some time later FPE Canada became Federal Pioneer and is now part of Schneider. But the fuse division never made it that far so nothing of the old Economy Fuse Mfg. Co. exists any more.

There was nothing very special about there fuses however (other than being made with asbestos, which became problematic later and likely why nobody here picked up the mantle). most of the big fuse suppliers will be able to cross over old Economy Fuse part numbers to several current brands.

" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

Try Monsterfuses. They are very good at sources all types of obsolete fuses.