Stan
One final note. I just now needed some Pumice as a filler additive, so I looked for it,and found that it is readily available as a cosmetic material in a couple of grades for skin scrubbing. The 4 grade appears to be the same be the one used for filler.
I also found that rottenstone is a form of pumice with a finer grind. It is sold as rottenstone and also as something called Tripoli abrasive. It is not easy to find, but I ordered some from a link on Etsi at $10 a pound and Luthiers Mercantile (lmii.com) has it on closeout at $7 for 8 oz, part number FPROT.
If you go to this link
https://www.lmii.com/blog/2017/10/07...polish-finish/
and read it and the suggested links(the links are much more detailed than the detailed summary)you will find more information than you want to read on French polish, shellac, shellac oil mixes and all the variations.