hello there, greets from mexico!
yes indeed, there were sunn (as well as accoustic) amps licence-built down here, i guess it must've been in the mid-late 70s until the early 80s. they do still pop up quite often; concert lead, concert bass, alpha 4, 8 and 16 mixers, concert slave, and yes, the concert lead II and concert bass II. those II-series are all-black and kinda ugly looking, but they're MONSTERS!!!
all the above mentioned came out mostly with english labels, but some were also made with spanish ones: volumen, agudos (treble), medios (mid), bajos (bass), etc.
quite rare, good, durable rockers... and certainly a good conversation piece if you have one... on the northern side of the border!
good luck,
Pat.