Just got hold of a lister d and domestic water pump

Hi guys as the title suggests I’ve got hold of a lister d and domestic water pump 187
I know nothing about the pump. Do I need to drain it after use? How often do I need to oil it and where? (That removable cover I imagine)

Can anyone help with instructions and maintenance please?
It does run well though

I wouldn't bother after use, but you will certainly need to drain both the engine and pump over the winter period.

Frost does not respect old iron.