Crossover / Fuse Repair, Blown Tweeters

My old Optimus PRO LX-10 Tower stopped putting out to the tweeter. I opened up the cabinet and found a "light bulb fuse" (with metal caps on both ends) that was hard-soldered in, and it's blown.
Here's the problem I'm having...
The fuse is a Stanley "27W 12V". I was told it's an automotive courtesy lamp. So, I went to the auto parts store, and they have a ton of similar 12V courtesy lamps, but none are 27V; they are 5V or 10V. I've checked high and low online and can't find it anywhere.
My questions are:
Can I use a different voltage courtesy lamp? Is there a different kind of fuse I can use instead?

Part 2:
I've blown the Linaeum tweeters on my LX10's twice. Is there a different fuse I could use (instead of the one mentioned above)that would blow before the tweeters do?

I realize it's probably user error that blew the tweeters (read: I cranked the stereo too damn high), but I'd still like a little added protection.

Here are the factory specs
Frequency Response: .................... 45-25,000 Hz

Power Handling: ....................... 80 Watts (RMS)

Maximum Power: .................... 160 Watts

Impedance: ................................ 8 Ohms (Nominal)

Speaker Complement: .. 7-inch (17.8 cm) High-Compliance Woofer

2 x 4-inch (5 x 10cm) Wide-Angle Dipole Tweeter

Thanks in advance for your help!
If you keep blowing drivers and fuses, you probably overdriving your amplifier causing it to clip and send trash to your speakers blowing the drivers ... upgrade your amplifier so it stops sending trash to your speakers.

Or it's time for a speaker capable of higher SPL.
I am in no way an electonics engineer (actually I am an optometrist...), but I have a friend who is a computer engineer. He says that replacing 12V with at 10V will cause no problems.

As to changing the value of the fuse, he recommends against it. Apparantly it will limit the power that can be passed thru in a way that will not enable you to listen at high levels reliably. Additionally, it is unlikely to prevent harm caused by clipping. As cytocycle stated, upgrading your amplifier may be the only answer here...
Thanks for the reply.
I must correct myself, I meant to say that the store has 12V lamps,but the watts are 5 or 10 (instead of the 27 on my original).
So, can I use 12v 10w or 12v 5 w lamps