I don't think anyone really knows what you're asking. What do you mean
by "custom headers" in a find? Headers have nothing to do with an AR
find. Are you talking about browser headers (I guess it's something to
do with a browser, as you mention cookies, but you don't say anything
else about the problem domain.
I've tried to monkey paths rails to do this, but didn't work.
What "didn't work"? What was the functionality you were trying to
achieve? How did you try to patch it? What result did you get (which
as you say, wasn't what you wanted - but *something*, even just an
error, must have happened).
Of course... you pointed the ActiveResource, and I've assumed
ActiveRecord. Sorry for that. But still, you're not really doing
enough to answer your own question: