Castagnari Cortina in DG two row, 4th button start with standard low notes and accidentals, three voice LMM with one right hand stop to switch the low voice in or out. Antonelli tipo a mano reeds. This is model was produced in very small numbers in the 1990s and features carved front panels. There are 12 bass buttons with 4 stops to switch low voice and thirds. Comes with a hard case and two padded shoulder straps. There is an old Castagnari catalogue listing here
Full overhaul and tuning completed with new vales and wax.
The extra basses are A/Bb A/Bb nearest bellows, and F/F# F/F# furthest from bellows.