I am sure someone here has the answer to this question.
How many different (not road names, actual types of) steam engines, diesels and electrics did Lionel produce in the post war period, and later periods, divide the periods up as you see fit. Example: 646 and 2046 is one type.
How many did MTH do in their life time.
How many did Williams do...
How many did Weaver do...
How many did any of the other manufacturers do, include as many as you wish.