Several firms did varnish their grips as mentioned, and like the lacquer on many scabbards, it didn't hold up very well in some cases. Bickel is another SA firm that you see with a varnished grip as well. I know that Houston even mentioned that the blonde Pack grips he didn't recalled in his early collecting days. None the less, the Aesculap dagger is near mint and dons the original color of the carved handle as it was initially. I think that this is probably what you are seeing many times when you find an SA with a lighter grip at shows, on dealers tables and on their sites.