oops, yeah I did read the fuse wrong, those commas as decimal delineation confuse me sometimes, sorry bout that. Too small should be perfectly fine with an audio amplifier as long as it's not producing powered output. So start it up without speakers connected and use any slow blow fuse over an amp or two. The filter capacitors hopefully won't trip a slow blow fuse.
I wouldn't trust a meter as a fuse reader, fuses generally need to be tested under load, which is why they're typically tested with a couple AA batteries and a simple low voltage light bulb that draws a couple hundred ma.
Radioshack would not touch that with a 10 foot pole. Removing that would require a small roll of solder and a soldering iron, apply a little extra solder to the back of the board where the fuse leads are, then heat both solder blobs up at the same time while pulling on the fuse from the other side of the board with a pair of plyers. You could try a solder sucker or solder wick but personally I have really bad luck with the stuff.
Something doesn't feel right about that fuse as it's definitly not a typical fuse form factor, they're usually long glass tubes so I'm not sure if there's anything specific about it that might be important. It's just odd because primary protection fuses should be designed to be easily replaced.