Rainsoft regeneration plunger

OK so I worked out the best removal process. It actually works better if you unscrew the large flush white plastic star cap/housing first then slide it up to the silver T bar with the tab for the index wheel groove and pry between the brass housing and the underside of the white top/housing with increasingly larger open ended wrenches/blocks.

Does anyone know the size of the three o rings on the vertical regen plunger?

Thanks,

George

I am going to try a 3.5mm x 26mm OD o ring set. That looks to be the closest.