I remember seeing at least three buskers playing a Johnson resonator guitar in the French Quarter in January. Best way to compare the sounds would probably be to hear a different brand. Is Roberto Luti (also of the Washboard Chaz Blues Trio) still playing with Mountain Sprout on the streets? He is a really good slide guitar player and his rust-coloured resonator definitely looks great!
Regards
Ernest
P.S.: I will get the copied cd on the weekend. My friend Doc - who agreed to copy it - is freshly retired and of course didn`t find the time to do it earlier ;0)