[exray]

Often times a high voltage cap was specced because it had lower leakage than a low voltage capacitor. This would be the case with C4, C3, C10. Not an issue with modern caps.

I'm not seeing C1 but C11 indeed needs to be 630 or greater. Radioroslyn's recommendation often helps but this cap is already tied to the screen. A 630 volt isn't going to just blow up - in fact it may last forever since modern caps are so much better than their predecessors.