[Phlogiston]

My way of thinking is to try to get that 630V Solen into the first filter. It takes the most abuse. Then if Solens won't fit in all of the other cans you hope that 450V Nichicons will last a long time if the working voltage is only 250 or 300V. (running a 450V electrolytic at 300V will have a longer life than one run at 450V).

Also if you have not seen:

https://www.mouser.com/ProductDetail/Nic...RXz3wlg%3d

You can get 3 of this series into many cans.