New restrictions on the movement of wood from protected species are causing problems for musicians travelling with older instruments:
If people can’t prove where every part of the instrument originated from, they could have it seized and be slapped with a fine (whether the instrument is factory new or decades old doesn’t matter).
If you are the lucky owner of a 1920s Martin guitar, it may well be made, in part, of Brazilian rosewood. Cross an international border with an instrument made of that now-restricted wood, and you better have correct and complete documentation proving the age of the instrument. Otherwise, you could lose it to a zealous customs agent—not to mention face fines and prosecution.