I am having a bit of trouble understanding the bolded portion of this quote from The Remains of the Day by Kazuo Ishiguro:
I had got no further by the time I came to have my first business meeting with Mr. Farraday during the short preliminary visit he made to our shores in the spring of last year. It was on that occasion--in the strangely bare study of Darlington Hall--that Mr. Farraday shook my hand for the first time, but by then we were hardly strangers to each other; quite aside from the matter of the staff, my new employer in several instances had had occasion to call upon such qualities as it may be my good fortune to possess and found them to be, I would venture, dependable (Ishiguro, p. 6).
Out of context, I might have interpreted this quote as the narrator stating that Mr. Farraday had previously praised ("call upon") his character and/or skills ("qualities"). However, the narrator is a butler for an estate and Mr. Farraday is the new owner, and given the fact they had not previously met in person, this interpretation does not seem to be correct.
Instead, I think the narrator means to say Mr. Farraday had previously requested ("call upon") the narrator's services ("qualities"), which could have been done before they met in person. In this context, the description of the narrator's "qualities" as "dependable" also makes a bit more sense. However, it does feel odd to use the word "qualities" to mean "services."
Is my interpretation correct? And if so, is there a reason behind the word choice?