Board finish

[Joe And Penny Goss]

Hi,
Had a call questioning the finish on the sound board of a S&S.
I did not ask who had done the work but it was a local tech. 
They had used poly urathane and the coustomer wanted to know
if this would compromise the value of the instrument.
I got the feeling that they felt the instrument was nolonger a S&S
since that was not the original finish that was used.
I may be using some of your answers in follow up to her 
Thanks
Joe Goss RPT
Mother Goose Tools
imatunr at srvinet.com
www.mothergoosetools.com