Is the fuse REALLY meant to be 10amp? maybe it's a 15A or 20A? (My stellar wars uses a 20A for the GI lamps).

Also, i know this is a pain, but remove ALL the GI lamps out of their sockets and replace the 10A fuse, does it still blow?

If it blows, then it proves a socket is shorted,
If it doesn't blow, then you proved a lamp is dodgy.

Replace the lamps back into their sockets one-at-a-time until the fuse blows again, then you've found the dodgy lamp.
(this is easier than measuring each lamp individually, trying to compare all the filament resistances, trying to establish what value is good or not).

Good Luck,
MM.