That or similar letter has been appearing in a number of "tractor" and equipment magazine for a number of years.
My biggest ***** about the letter is the"trademark" angle. What do you think people would say if FORD says no one can sell FORD vehicles used because that would violate fords trademark in the ads. BS..... While yanmar is right the Greys dont have some safety, but a 47 Chevy doesnt have air bags or seatbelts either. The US customs has seen fit to let them in, to "legal" status is not an issue. They are US legal . There are some OSAH issue if used in commercial work, but for private use there is none. ROPS, no problem, my yanmar doesnt have one nore does my John Deere B, PTO shield, My yanmar has one my JD doesnt, Over running, Again an issue but easy to correct and a issue with older tractors as well.
The PTO is the only BIG ISSUE but a metal stop could solve that one. Decals for warnings, Again not in english but missing from many used tractors. If this is such a big issue for yanmar why not allow someone to legally translate it.
To me this is a classic CYA from the legal staff and maybe even a CYA from a JD agreement.