Hi Roger. For years I tried to get a REALLY heavy bass string in order to tune my '58 Harmony Sovereign down to BEADF#B. No luck until Sandy Paton suggested that Gordon Bok may have used custom strings. Shortly after that I obtained a "67" and realised that Bok must have been a wrestler at one time. The perfect string was a La Bella silk and steel "68", earmarked for Pete Seeger's use. It's beautiful and I got them to send me a dozen....and then someone stole the guitar! (along with my car) I got the car back but not my precious 12 string. It was the only one I've ever owned that really sounded good tuned that low.