for different markets the frame/engine numbers can be different. e.g. the 1VJ is here in Switzerland a 1VK and the 3AJ is a 3DS.
as the Tenere and also the XT600 was also made in Brazil - most of time the engine parts came from Japan - your bike could be from Brazil. Or just for a small country with special requirements. But this does not mean that there is anything different inside your engine, most of time Yamaha changed just the jets in the carbs and the lights.
I dont know any other way to find out, than to post in the all the xt forums around the world, maybe somebody knows.
enjoy rebuilding the bike