Brownie points

[Douglas G. Wilson]

Michael Quinion discussed possible etyma for "brownie points" recently.

I see HDAS derives the expression from the Brownies (branch of the Girl
Scouts), which is not implausible IMHO.

Quinion has presented a few other theories (unsubstantiated, I think). I
have (of course) a naive dubious notion of my own, but before I embarrass
myself again I would like to ask Jonathan Lighter and all the other scholars:

(1) Is *any* expression of the exact form "brownie point" definitely
attested before 1951?

(2) Is it certain that there was a previous entity called a "Brownie point"
within the Brownies organization, or is it simply assumed that  anything
called within the Brownies a "point" could be called a "Brownie point" by
outsiders? Is there any known record of a literal "Brownie point"
(referring to the Brownies) and if so from what date?

-- Doug Wilson