It just so happens that I have a Bianco Freres (piano) accordion. I got it for free, intended to be used for parts, but I found it too good to just use some parts and then toss the rest. It was a bit of an oddball: LMM but with the second M lower instead of higher (as is common). It was an 80 bass accordion but the row of 7th chords had full chords (so C7 as C-E-G-Bb) making them unusable for diminished chords. I carefully removed the stub for the base note from eash 7th chord piston, (making C7 into E-G-Bb which can serve as G diminished). After tuning the accordion became more or less usable, good enough to donate to a beginner in need of an accordion. (That beginner still has not shown up...)
Apart from these two quirks it is a decent starter accordion, not better or worse than German or Italian ones from that era (and better than a Chinese).