Welcome Hans.
That's an electric shift Stringer. You can ID it by the HP of the engine, and in the engine bay ... typically on the starboard side toward the back, there is a tag that will have a number on it (it would read like JUFM10S some thing like that). You can figure out what you have from there.
Stringers of that vintage didn't really have model numbers that meant anything.
The impeller is at the bottom of the upper gear case. #31 on here:
Best to remove the drive to get to it. Otherwise, you are working upside down.
