Circa 1970s Hanimex model 101 record player with built-in pre- and power amplifier PCB stopped outputting audio signal. Found PCB glass-body fuse non-functional. Fuse has 'CONO GDL' and '0.5A250V' etched onto it. Board says '500 ma ANTI-SURGE'. Fuse has resistor in series with a coil of wire in it. Resistor colour code is: brown, red, gold, gold = 1.2Ω/5%. This is a slow-blow fuse, right? Can't find anything similar from Google search. Can I just replace it with any modern 0.5A, 250V slow-blow fuse?
Yep from the markings you've mentioned, that's just an old slow blow glass fuse. You should be able to replace with any 0.5A 250V slow fuse as you rightfully mentioned.
They used to make them like that so that the solder would melt when the resistor got too hot (my guess is it was easier than manufacturing ultra-thin wires like nowadays).