Both of your motors are from the mid-1990's. We service a lot of these in our shop (freshwater small-sailboat auxiliaries), and they are almost indestructible, as long as they get proper maintenance.
There is no site that provides model years off of serial numbers as Tohatsu/Nissan has never thought it necessary to create any kind of chart. You can contact them directly at info@tohatsu.com with the serial and model number and they might be able to identify the year for you....Model years are not used to determine what part is used on one of their engines so the year has never been important.