"Vitamin Q" Caps

I came across four "Viatamin Q" (no kidding) caps made by Sprague rated at
25,000 VDC at .0127 mf.  These things look like oversized glass instrument
fuses, about 2 1/2" in diameter with metal caps and threaded studs at
each end for connections.  Has anyone ever come across these or used them in
Coil operation?  I'm a bit concerned about PCB's because of the glass envelope.
They seem to be a great match for a 10KV transformer. 

Don Froula