I have a book by Nancie Wiseman "Lace from the Attic: A Victorian Notebook of Knitted Lace Patterns". The author (Nancie) was gifted with a old old old notebook filled with lace knitting patterns when she owned Nancie Knits in California. A lady named Madeline Eid walked in one day and asked Nanice if she'd like this old book of handwritten lace patterns by Miss Blanche Beau. It had been recovered from the attic of an old Victoria house.
Interpreting the abbreviations turned out to be a great challenge.
Anyway, after much research and lots of help from old time knitters, Nancie was able to decipher these abbreviations, and the book Lace from the Attic contains all the lace patterns 'deciphered'!
I looked in the book for you. Blanche used the term S and B for 'slip one, knit one, pass the slipped stitch over'. S and B means slip and bind off. B meant bind off. S meant slip one.
And O meant yarnover, as you now know, as a increase. N meant K2T as a decrease.
OSN meant yarn over, slip one, K2T.
I don't know if this is helpful, but I hope it helps you solve your mystery.