The Pipe Collector had a recent article about the Elephant & Castle blends. Two Seigel brothers were the importers (and also Marble Arch pipes). One brother, Peter, is a occasional PipesMagazine forum contributer. I've communicated with him via email. I started this thread on that forum:
http://pipesmagazine.com/forums/topic/elephant-amp-castle-tobacco-article-the-pipe-collector
Peter is member "neverbend" and adds some additional information. I'm still hoping to meet him some day and crack open of his remaining tin inventory.