This is the first, and may be the last time that I've worked on a purple virginal!
Over time the soundboard on this virginal had bowed and the bridges had sunk to such an extent that the tenor strings buzzes against the soundboard when plucked. Attempts to raise the strings off the soundboard by fitting 'happynes posts' under the bridge resulted in raising the area of soundboard that was touching the bass and tenor strings so the 3-4mm of clearance needed between the strings and soundboard was not achieved. These sprung posts also deadened the sound of the instrument to some extent so they were removed again.

It was time for an more radical solution which would avoid replacing the soundboard altogether. I removed the strings and bridge pins and took a rubbing of all the bridge pin positions. I then trimmed the top of the bridge to give a straight glueing surface and made an additional wedge shaped section of bridge to fit on the original bridge. This was glued and secured with masking tape, but not before the pin positions had been marked on a strip of masking tape placed along the length of the bridge.
 
This bridge was then trimmed and drilled for replacement pins and the instrument was restrung. It now plays nicely and there is 6-8mm clearance between the strings and the soundboard. 

I'll soon be able to go sailing again!
 The 'Tallships Youth Sailing Trust' does adult voyages too!