Royd Minstrels. Steve Edmundson has kindly sent me some scans of original literature that came with his Minstrels. These include the full spec and Royd’s own description that helps put them in context.
Recently ace-reuse-kettering on ebay sold a pair of Minstrel SE’s with the rate steel base. This optional base was studier and gave extra support through a rear vertical brace the Minstrels could rest against.