You might want to try the website for a radio show called Harmonia: http://www.indiana.edu/~harmonia (blue clicky monster didn't want to work). And if you live in the USA, you might want to see if a nearby university radio station gets the show. Or maybe you could listen to it on your computer.
I haven't got the time to look it up right now, but if your group gets really sticky about things being in period, your bowed psaltry might be too new. I seem to recall someone saying it was developed by the Germans to teach bowing technique in the ?18th? century. I'll see if I can track the information down later. And I won't tell on you if I see you perform.