The handlebars have been flipped to make for a racier ride; hard to say whether they're original.

I'm sure the chain ring is well made, but its not at the upper end of the quality range; the single chain ring swaged to the arm indicates a bottom end chainset. Bbetter chainsets had removable rings attached to a swaged-on spider, and the best ones had the drive side crank arm forged together with the spider.

I wouldn't put much stock in the name "renown." It's just a name. Love that head badge, though!

Andrew, does this bike fit you? Are you riding it? And where? We should get a bunch of guys together for a "clubman" style ride-- basically three speeds with drop bars. When the weather improves, that is.