<img src="images/graemlins/grin.gif" alt="" />. By sparking wheel, do you mean something like the sparklite? I still can't quite picture this. So the main tool would act as the handle and the sparking mechanism would stick out unprotected? I don't think is what you mean is it.

Your idea about cementing the ferocium to a piece of metal and inserting it in to the scale seems feasable. However this would soon wear down and wouldn't be much use in a survival situation (better than nothing albeit).

That quick release thing looks like a good idea. I use a metal one like doug has on my keychain, but plastic would be better as it wouldn't knock against and chip the hotspark.

All good ideas so far.