Lister domestic water pump

Hello all,
I moved house last year and my new place has a working well and a lister water pump plumbed to it. The pump wasnt working so I overhauled it and fitted bearings and seals etc, all the usual stuff that spoils over time. The pump has been used a lot as the mains water only reached this place 20 years ago and this was all they had (it's an old farm). The people that were here before me lived into their nineties so there's maybe something in the water!!

This pump will be in daily use and will be handy when the water charges begin as I'm metered at present. You'll see from the video that a box is attached to the side of the original Hoover motor and from what I can ascertain it is a run capacitor to "help" the motor along, like a donkey with a carrot dangling in front of it. It is separate from the start capacitor which is on to of the motor (the bulge).

I seem to have oil leaking from the rod through the crank case to the piston. I ordered a seal but it is much to small on its outer circumference so I must be missing something. At present I only have the metal plate with the hole that the rod goes through, sort of dish like.. Any help would be appreciated.

Here is a link to the video I took and posted on YouTube

https://youtu.be/OFAV9R61gqY

Thank for any comments

Stewart