Thanks for that, tsuwm - interesting (if true to type) that he got so ratty at the suggestion of a 'low' origin! fwiw, I can not track down any conceivable link to a Scots Gaelic or a Welsh linkage of any kind closer than the utmost improbability. Looks like its origins may genuinely be lost in the mists of the 16c and earlier.

Fong, d'ya feel like floating it at w/o? (I haven't got time to visit there in the next few days or I'd try it to check the other resources but.)