Topband: Feeding 160M Vertical on 80M

[Bob K6ZZ]

Folks,

I have a 60' tall top loaded vertical for 160M and would like to know how
best to feed it to use it on 80M as well.  On 80M there will be some pretty
high voltages at the feedpoint.

Other than dealing with high voltages, is doing this a bad idea (or good
idea) for any partcular reason(s)?  The high current point would be higher
above ground which seems beneficial at the very least.

What would be the best method for matching it on 80M?

Do 1/2 wavelength ground mounted verticals require the same quality ground
radial system that 1/4 wavelength verticals require?

Thanks and HNY to all!

73, Bob K6ZZ