Suggestion meet solution
Just checked my emails, these were the specific problems I had
1. UPS refused to collect due to the value of the bass which meant I had to take it to a 'Service Centre' where the staff had apparently no idea what to do with the paperwork and at least some of the documents didn't make it to the US
2. It was almost impossible to identify the correct import code, which IIRC we eventually had to leave off the form which further slowed down the process
3. Despite the buyer repeatedly speaking to them on the phone, UPS kept emailing me new forms to complete requiring the information the buyer had already provided (these were almost certainly system generated but I got the sense that phone conversations and digital comms were completely independent of each other).
UPS tracking was also a disaster, we received 'Out for delivery' emails followed by 'Your item has been held by Customs' emails frequently
Eventually Rob at Status provided the necessary information, which IIRC was related to the material of the neck inlays, and after a few weeks the bass was released.
I have a friend who like @walshy regularly sends guitars to the US, his view is that it's generally ok but that when it goes wrong it goes spectacularly wrong, guess we were unlucky
In the grand scheme of things, all unimportant stuff. But it was an expensive and rare instrument and myself and the buyer had three weeks of worry about losing it, something neither of us could really afford to do, especially as it was a little ambiguous as to whether the insurance would cover an impounded instrument, I suspect not.
But even though I might have been unlucky, I will not use UPS again, ever 😡