Just acquired this bargain on eBay -
A 1940s Vortexion EG 20 electric guitar amplifier. Must be the big brother of the EG 10, as advertised in 1947.
The amplifier is complete and very clean so my plans are to first do a minimal restoration to get it working in as close to original state as possible, then convert to safer AC use only with a modern mains transformer and 4 x EL33 to replace the CL33. Though I suppose that 2 x 6L6G would give similar performance.
I'll keep notes on the restoration here