That is the information I needed, Dave. You have a horizontal shaft engine of 3.0 hp, made in 1980, 1990 or 2000 (the date code doesn't tell us which) on the 151st day of that year, on production line B. Presumably the 1980, 1990 or 2000 question is resolved by the type of engine it is. The "specification number" (similar to Briggs' "type") is 35311S, and in combination with a parts list I don't have, that might give the answer. However I think a 2000 engine would be a low emissions type, with a number beginning with "LEH" instead of "H", so it is probably 1990 (it doesn't look old enough for 1980 to me). Very likely a serious Tecumseh guy would recognise the engine, or its paint colour, or some other feature as we often do with Briggs engines, and know which decade it was made in.
