[Hiwatt]

I recently picked up a Philco 41-296, beautiful unit, but needs a lot of love. I am self taught at this and the vast majority of restorations I have done are on British Guitar Amplifiers, so I am not quit up to speed. My question is about the filter capacitors, there are two a 128uf @ 400VDC and a dual can 8 uf & 16 uf @ 400VDC. Can these capacitors be replaced with modern electrolytic? If so will it matter if they are polarized or not. Second question concersn the res of the Philco labeled Capacitors inside. I was told it is a good idea to replace all of these, however, I have tested about half so far and all are with in tolerance on my meter. Is it necessary to replace these?

Thanks in advance for any help.