Kevin, I have a 1973 Sunn ConcertBass Amp and 415M cabinet for sale. I purchased the amp and cabinet in 1978 while in High School and used it for many years. The amp and cabinet are impedance matched and very loud. The only changes was new grille cloth for the speaker cabinet (regrettably not the silver Sunn clothe - I recently found out the original cloth is available from Fender). I have never seen another 415M cabinet and have not found it in any Sunn brochures. I used this amp (my first) until 1996 when I bought a new rig, but I have not been playing much lately and think my old Sunn deserves a new home. Asking $350.00 If interested, call 561-302-4470 (Southeast Florida) or email bassman33428@yahoo.com
