Ten. I'm just not that interested in mono pressings, tho at one time I had the history of WWII on 33s called "Sea Fights and Shipwrecks" that was very interesting. I also had a record that had eathquakes and Ionic storms, but that is gone too.
I do have the Bob Dylan Highway 101 Revisited in mono and a I thought my 1812 Overture (with canon) was mono, but I'm too lazy to get up and go look for it.
I did convert some 1940s stuff to CD for a friend, all older comics like Bennie Goodman, Abbott and Costello and some guys like that. That was pretty interesting. I suppose if I came across some stuff like that, I'd buy it.
Wayner