I'm intrigued by your description. I don't think it's Minstel style - from what I've read and heard that's a "stroke" technique similar to frailing, and not necessarily a "fast" sound.
I've got a Brad Leftwich old-time fiddle instruction video and his wife plays back-up on a banjo uke,which I first thought would be funky, but was actually quite effective. It wasn't especially fast either, however.
Although I'm not an expert, most of the old time bands I've seen pictures of were using a 5-string, without resonator.