the original C26 should be 180uF at 350VDC and it's an axial type. Lead at either end as opposed to radial like C23, leads at one end, and make sure the orientation is correct if you get an axial, also make sure the negative and positive are correct with the radial, the outside of the case will have an indicator of what's what.

anything from 150uF - 180uF (if you can find one?) at at least 300VDC, ideally I'd go 400+VDC.

you may struggle to find an axial type and may have to choose radial which will still work fine, just adding a longer lead.

suggest reading and doing the upgrades: https://www.pinwiki.com/wiki/index.php?title=Bally/Stern#Solenoid_Driver_Upgrades