Repair questions

Hey folks,

So I just inherited the last of my Uncle's gear.  Along with a Rega Planar 3 he purchased (and modded) in the UK 30+ years ago, I now have a Jolida sj 502a.   There are some extra Sovtek tubes, etc in another box.

I have been wanting to try tubes for a while.  But my uncle said this Jolida has been blowing fuses lately.  
The specs indicate using 6.3 Fast Blo.
Does it matter what kind? Glass? Ceramic?

Searched the threads here but couldn't find much info on this fuse issue.

I also know very little about tubes.  Have been warned to always have speakers hooked up before testing, etc.

Should I try to find a local shop to have it looked at?
Or are there things I can do to troubleshoot?

Thanks!