40k is good mileage!
i would rather buy a 126 with higher milage as these tend to be the more reliable ones, they have been maintained, and like anything mechanical they have to be used or go start to have problems.
i would change the oil as often as you can afford to, and fit a few filter before the pump, and get the king pins greased every couple of months or so.
congrats on your purchase!
regards
Chris