Nothing wrong with "Ms", see my signature. actually there are a ton, well maybe not a ton, but quite a few, slope shouldered 12 fret Ms around, Almost by definition any 12 fret Martin dread is a slope shoulder with slotted headstock, 6 or 12 string, with few exceptions. Don't know the numbers but Martin's first commercial 12, the D12-20 came out in 1966 and was at least available until 1975, maybe longer so thats at least a 10 year run for one model alone. The -35s are all 3 piece backs, initiated to salvage Brazilian when it started to get scarce and there were fewer big pieces available for 2 piece backs. Now even though they are EIR they retain the 3 piece back. Bracing on -35s is also different than on the -28s. For all this guitar weenie stuff go the UMGF for more gory details.
Nice score, very reasonable with shipping, and looks in really nice shape. Always worry about neck resets with old 12s.
BTW after 1968, all Martin 12s could be safely tuned in standard with the usual 12 string sets.
Harmony H-173 bought in 1960 (retired), Alvarez AC60S 2008, Eastman AC320ce 2008 "Hybrid", Guild D25M 1974, Martin Grand J35E 2009, Martin D12-20 1970, Martin OM-21 2009, Martin 00-15M Custom (full gloss, wide nut) 2011, Voyage-air VAOM-06 2010
"I'm glad there are a lot of guitar players pursuing technique as diligently as they possibly can, because it leaves this whole other area open to people like me."
Richard Thompson