Welcome noidea!

Nice clear photos: thanks!

It's made by the oldest accordion making firm ( no longer in the direct line of descent): a good solid model from about the 1950s, for the amateur player ( but not in the upper echelons, a sure sign being the giveaway repetition of two of the coupler switches.)
In very good cosmetic condition!

Three treble voices (LMH).
120 basses.
Effectively 7 treble and 2 bass couplers.
Probably from the 1950s

We could do with another photo showing the tips of the white keys to check whether they may be in the "waterfall " style.

As to value, much depends on the condition of the insides. Is there anyone who could play it for you to see what shape it's in?