R 40 speaker - fuse?

[Don Mackie <donald@iconz.co.nz>]

I am going to look at a C3, ex church with 2 122 Leslies and, they tell 
me, an R40 speaker. The R40 is apparently not working due to a blown, 
'special' fuse. 

What's an R40? If they are right about the fuse, what kind of special is 
it likely to be and why might it have blown (concealing worse badness).

That said, the C3 with twin Leslies sound OK to me, I can live without 
the R40.

Don Mackie
at home