Early A-4 (1965)-water pump

[quiesence65]

First of all, my water pump is working perfectly, even after sitting dormant for two seasons. However, I would like to change the impeller, but since it too has been two years since I've done it, not sure that I remember the make......although the name Sherwood comes to mind. Also, I would love to put a quick change plate on it, but they have 4 screws and mine has 6.
Questions..... (1) does the name Sherwood mean anything, and if so, where can I get an impeller? Does MM carry them?
(2) Can I put a quick change plate on anyway?..will the 4 hand tightened screws with the O-ring be sufficient?....has anyone done this?
Could simply change out the whole pump.....but would rather not....if it is working, don't fix it!!!!
Thanks.

[thatch]

Sherwood supplied three pumps for A4s. Two of them were similar to the block mounted Oberdorfers and the third was used with the fresh-water conversion. The two raw-water pumps use the same impeller. In the "notes" column in my A4 parts manual the numbers L9960 and T-11165 show up which may be Sherwood #s.
On other brands of pumps, like Jabsco's, the pump model number is on the impeller cover plate.
Tom