I’ve come into contact with one of these pitless’ before, however never needed to buy new o-rings as the old ones held up just fine. However when I pulled this one the o-rings were rotted and unusable. Has anyone ever worked with these Advance pitless’ and would anyone know what size o-rings to order for one that has 2” drop pipe attached so I don’t have to order a bunch of them? Any help would be greatly appreciated!