[codefox1]

Use diecrete components, just order 400 VDC replacements, they are tiny and no worry about limits. Do not bridge old components, cut them out and discard them. Replace with values equal or just above original capacitance values.
Big useful list of vendors here:
http://antiqueradios.com/forums/viewtopi...9&t=201537, hobbiest friendly site also here: http://www.justradios.com/
Bear in mind that you should also replace all the paper or wax type capacitors at the same time for a start, and you might find it prudent to replace old carbon resistors as well.