Norman,
Hate to break it to you, but I think there's a bit of urban myth in that story.
I only have records of 5 B&W FCs, but every one has a late '59 body number. Also, of the 5, 2 are Melbourne built, 2 Sydney and 1 Adelaide.
The codes 299 and 300, for White over Black and Black over White are at the end of the range of FC exterior trim numbers, and amongst other colour combinations introduced in late '59 as well. I don't have specifics of when colours were introduced, but others here do, and might be able to provide further detail.
Can you post ID plate and chassis details of your car?
As an aside, I did clearly recall a NSW club member from the early 90s that had a White over Black FC Special in the early '58 paint style, which contradicts what I wrote above. However, having dug out the old research form for that car, it turns out it left the factory black all over, and the white was added later.
Hope all that is some help.
cheers
RET
(fellow lifelong Magpie supporter, of the "proper" ones: Western Suburbs Rugby League Football Club
)