(From The Wrecker by Robert Louis Stevenson and Lloyd Osbourne, Chapter XI, published 1893)
Passage 179
Never was a man so lucky! You and me and Mamie; it's a triple cord, Loudon. If either of you were to die! And she likes you so much, and thinks you so accomplished and distingué-looking, and was just as set as I was to have you for best man. 'Mr. Loudon,' she calls you; seems to me so friendly! And she sat up till three in the morning fixing up a costume for the marriage; it did me good to see her, Loudon, and to see that needle going, going, and to say 'All this hurry, Jim, is just to marry you!' I couldn't believe it; it was so like some blame' fairy story. To think of those old tin-type times about turned my head; I was so unrefined then, and so illiterate, and so lonesome; and here I am in clover, and I'm blamed if I can see what I've done to deserve it.”
So he poured forth with innocent volubility the fulness of his heart; and I, from these irregular communications, must pick out, here a little and there a little, the particulars of his new plan. They were to be married, sure enough, that day; the wedding breakfast was to be at Frank's; the evening to be passed in a visit of God-speed aboard the Norah Creina; and then we were to part, Jim and I, he to his married life, I on my sea-enterprise.
I'm not sure of the meaning and function of the word about there. Does about belongs to think as the particle or preposition or does it belongs to turned as the adverb? I take it to be the adverb of turned and to mean something like 'nearly turned my head' or 'completely turned my head'. Am I on the right track? I haven't come across the word about of this meaning. Is this common usage?