need some large cap reassurance or feedback

[kvb]

I am refurbishing an amp that is 20 years old
I'm replacing the main power supply filter caps - one had a burnt lead that I fixed before I started the diy thing.

When I shopped for caps I figured 50V was just about as good as the original 55v. These are 4700u.

the schematic says that the power supply is putting out +/-42v.  So the 50v caps should be just fine - right?

I'm asking because the usual advice around here is to go bigger than neccessary to avoid problems in case of a spike or surge.
I'm also wonder if the original value of 55v (which mouser didn't seem to have in axial) was used because it would be half of 110v - 50v would not be.

I've got the 50v 4700u caps, but I'm just not sure that I should put them in.

[Gus]

I might go higher for the voltage rating.  Often the power supply is unregulated.  The USA power at the wall seems to be creeping up over the years.  I sometimes measure 124VAC at the wall sockets where I am.

The point of the above is older older stuff might have be designed for 115VAC input, if the voltage going in is >115VAC the output might  be even higher than what was marked on the schematic.

What is the marked input line voltage on the amp?

[kvb]

the schematic says 120v AC