It's not their kind of repertoire (or that of any present-day klezmer band), so I doubt they'll have encountered it before.

The words are very clear. Most cities in the West have a few Yiddish speakers and asking round a synagogue should locate one.

This page tells you how to contact the organization that hosts Yiddish Song of the Week. They could pass the request on to Itzik Gottesman (whose email address I seem to have lost). He'd almost certainly be interested.