This is a B-system chromatic button accordion (CBA) version of the Excelsior's model 980. The case is stamped as Mod. 922, which, afaik, was the highest model number for CBAs, but this one's different from a typical 922 as it's got the MIII freebass and chin switches on the right. I suspect this might have been a special order to put the B-griff onto the Mod 980 chassis.

Right hand side is 5 voices with double cassotto (L & M). Don't have the exact cents for the de-tunings, but to my ear the M reeds are tuned to swing for the main 2 voices, increasing to a pleasant sounding light tremolo (American?). 

There's certainly no dry MM sound and no very wet musette. 

Left hand side has got two voices (LM), with the lower octaves featuring extra-large (some might say "bayan style", although these are single-plate Italian reeds)) reeds. 6-row stradella is accompanied by the MIII freebass. 

I believe this model is from the 80s, so, as any used accordion, is not perfect, but in my opinion is in good condition. 

There is definitely scope for a trip to a repairman for a little service.

- Reasonably well-tuned to my ear, but if you want absolute perfection, I'm sure a slight spot-tuning can improve things.

- The higher range of the piccollo voice has got poor response, the very highest octave being particularly bad.

- You might get an occasional buzz from a reed here & there, but overall they appear to be in good condition.

- There seems to be a small crack in celluloid on the corner of the left case, just next to the air release button.

- Some of the celluloid seems to have unglued from the aluminium grille on the bass side, right next to the feet.

- Minor scratches & small dents to casework can, in theory, be polished out.

I've tried capturing the "well used, but good" condition in the photos.

Comes with an old soft padded bag that is very worn.

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