If on the page of N-Gram you link to, you click through "a few does", you will see in most examples the "does" in question is not the third person singular of the verb "to do", but the plural of the noun "doe" -- a female deer. Example:
I got in the stand before daylight, and by 11 o'clock I'd seen a few does and one fairly nice buck, maybe a 130, but I let him walk.
"A few" is plural, and takes "do".
Addendum: Oh, hey, google's N-Gram doesn't respect punctuation, and there's quite a lot of "a few does" hits which have punctuation between "few" and "does" which completely changes the relationship of the words. Examples:
Does she have many memories or just a few? Does she enjoy thinking about and remembering them?
Does that man take boarders? He takes a few. Does that woman keep a boarding-house?
Thus 'a few' does not rule out the possibility that an All statement is true. 'A few' is a positive quantifier, which Oaksford et al. designate by Few+ (Moxey and Sanford 1987, 1991; Paterson et al. 1998;Sanford et al. 1994, 1996).
It is an old maxim that "he who mentions a few, does not deny that there are more."
Apparently google's N-Gram viewer isn't necessarily so good for phrases.