Remember-at least in the US, when you renew your passport, you get a new number. The 10 year permit is tied to your passport, and number. So, as in our case, the motorhome was sold, we tried all the official ways to get the permit cancelled, without any success. Had to renew passports, and voila! No past history of our permit, because it was a new passport.
Someone, possibly Tequila published this information, and a website where this information could be checked by passport number. Don't know if this website still exists, or is current, but here is the link I used:
https://portalsat.plataforma.sat.gob.mx/aduanas_cpitv_internet/index.aspx