[TonyDuell]

I was given a 'Protector, Heat Coil and Fuse' as in the above photo last year. Mine still had the heat coils, but the carbon spark gaps had been removed and the fuses replaced with dummies. The dummies in mine was just flat metal strips with shaped ends to fit into the spring contacts. I've attached a photo of the insides of it.

If nobody else has a need for them I could add the fuses to my collection to go in that unit (which I will never use on a 'real' telephone line of course).