karen k,
Don't know the whereabouts of Mark (perhaps he'll show up - as did others I published a discography of ?!?)
His two first Folkways records (i.e. including "Club 47") can be ordered (19.95$ each) as custom made CDs at Smithsonian Folkways Recordings at the following address: http://www.si.edu/folkways/artist2.htm
(Meanwhile I added this information to my site - thanks for reminding ME)
Hope this helps at least a little bit !
Stefan