I found it interesting to read about those who are looking to purchase accordions, having concerns about quality, what to look for, and shipping , etc.
I'm sharing some of my "maybe ancient or redundant for some" experience only in shipping and hope it may help.
In the many years of both shipping and receiving hundreds of accordions in preparing, packing, shipping, etc. I've never had any damages or claims for damages by using the procedure taught to me in Italy by Excelsior both in Montreal and in Italy-- the original, not the current...
I'm aware others have used similar procedures.
All accordions, especially for international clients, first had a strip of cardboard inserted in the bass section 'pistons' to prevent the bass buttons from moving, with a short label attached to the instrument warning not to try the basses without removal, then the instrument wrapped in clear plastic, placed in its case with base section down of course - ( have seen some accordions shipped outside down even from owners!)...
The instrument then is surrounded by styrofoam sheets at the sides and front thick enough to prevent any movement when the case is closed, the straps rolled into a foam sleeve and placed on the grill. If needed, wrapping a sheet or 2 of crumpled paper to prevent the straps from moving as well. The case was then wrapped in plastic again to make it easier when removal at the other end.
Now the really important part... The shipping containers were always either double or triple thickness depending on the size and weight of the accordions and case and it was slightly larger than the case dimensions,. Accordion and case were placed in the carton after a layer of styrofoam was placed in the bottom of the container, then styrofoam sheets were inserted in all spaces at sides and top, basically to prevent any movement of the contents. The case handle was left open with a cutout of the foam so as to have equal pressure on all sides.
Heavy duty industrial packaging tape sealed all 6 sides. Address and Sender labels were also sealed with transparent tape.
We always added FRAGILE or DELICATE INSTRUMENTS labels on at least 2 sides and top - NEVER ACCORDION!!! - knowing that some hated the instrument.. And we added the word TOP and arrows pointing UP on all sides. Often took photos as well before shipping, and especially for hi-end accordions Always insured of course and any insurance fees were simply added to the purchase price or repair costs.
As said above, I cannot recall ever seeing a damaged instrument or making a claim. On receiving shipments, always checked the carton with the delivery agent present.
NEVER ever shipped an accordion without its case..... have seen it unfortunately... foam wrapping doesn't help....
Two things - I hope this was not patronizing and hope also it may help those who are looking at purchases from longer distances -
--good idea to request that level of shipping.. worth the extra cost....