An idea- try calling Citybikes in Portland. Last time I was in I seem to recall some new handlebars. They are small and very local so they are probably are unwilling to ship them and it wouldn't be cheap but if you said you were turned on to them by a customer of theirs for 20+ years whose spent a lot their, maybe they'll have an idea or source. (citybikes portland brings them up as almost the first hit on Duck-Duck.)
It didn't occur to me that you might have trouble finding what I consider so ordinary but I have spent the past 15 years stashing those HBs I like (bends and width) so what's available matters little to me.