Thanks John for the reply. That part number is for the Yanmar brand impeller. There is also a Jabsco brand impeller that works also, however, it doesn't have the threaded hub, so it is a lot more difficult to change out. Perhaps the effort, price savings ratio is not worth it.
The last time I had my impellers changed, the mechanic had to pull them with a conventional impeller puller tool - actually a very cool, long hose gripping pliers. They were the Yanmar brand impellers, however, the previous installer had put them in backwards so the threaded hub was negated, though they worked just fine for a long time.
If I figure out the Jabsco part number, I'll post it.
All for now.