as said above the small bearings are at risk of wear , as well as the lower counter shaft rollers , nothing lasts forever and high use spinning parts need to be looked at as well as the shift engaguement stuff , and thrust washers really anything that moves

You need to really know what your looking at to see damage or wear -

if you cant locate the last owner to speak to than put it in with new oil ,and hope for the best if its ok save up for a problem they are pricy to re do -- jz