I'm the proud owner of one of these babies.  I absolutely love the sound, and I think it's an amp that Nik could do well with sales wise.  The Fender Blond Twin had the same circuit (6G14).  I have NEVER seen a used 6G14 Blond Showman on eBay EVER! at least not a 60' or 61' model.  I really felt as though I had acquired a rarity when I came across this amp.  The late Jimmy McCullough of the band Paul McCartney and Wings had one or more Blond Showman amps, and some vintage Marshall 1959 heads running through vintage Marshall cabinets.