Ha, glad I'm not the only one, I went directly to Wiktionary after finishing the article, which doesn't mark it 'chiefly US' or anything, and gives RP IPA.
Which contains another surprise, for me anyway - it's not pronounced like the golf club, but starting like 'put' (that over there) or 'foot'.
Apple's Dictionary.app, which for me pulls from the New Oxford American Dictionary, does mention that potter is the British version:
> put·ter³ | ˈpədər | (British potter)
> verb [no object] North American
> occupy oneself in a desultory but pleasant manner, doing a number of small tasks or not concentrating on anything particular: early morning is the best time of the day to putter around in the garden.
> • [with adverbial of direction] move or go in a casual, unhurried way: the duck putters on the surface of the pond.
and defines potter as:
> verb British
> another term for putter³.
(It also has all 3 definitions of putter - golf, engine, gardening - pronounced the same way: ˈpədər)
Thanks. Hehe that's amusingly parochial. ("Whole World except USA" they like to call "British", and 'potter' is merely 'another term for putter'. Everything is inside-out.)
Which contains another surprise, for me anyway - it's not pronounced like the golf club, but starting like 'put' (that over there) or 'foot'.