It is no big deal.
Just call ISUZU (800-255-6727) and tell them you are the new vehicle owner, they don't ask for any proof. Give them the VIN and your name and address and they'll fax you a letter stating that the vehicle you have has no outstanding recall items. That's it - I got my letter a half hour after I called.

On other matters, I guess you have to get the headlights converted to full time. A warning if you haven't done it yet, it's a lot of wiring and it's not cheap. Make sure they do a clean job on the wiring and harnesses.

Good Luck.

Another one for Canada, eh. Cool.