FlickFlack,
AFAK, these accordions from the 1950s and 60s were reasonably well made workhorses for the amateur accordionist
not wishing to take out a mortgage, but less than at a competition/concert standard.
A bit like the good, reliable family car, not a Rolls nor a Lamborghini!

Nothing wrong with that, its what most of us have!

Four is quite a handful to get all at once.
What's the story: are you already a player or just ambitious?