Stradivari, when the varnish is missing

I had the chance to work on this violin, almost all the varnish is missing, and it has been overcoated with French polish over several years.  I find the tool marks clear and subtle, also I can see how well sealed the wood was.  I will not speculate what ground was used.  I had good results with mica and pomice.  I have also been using spirit terpentine and mastic for years with good acoustic results.  The pictures speak for themselves.