I dont particularly think that there is anything wrong with blacking up in context , I mean If I was to black up and get on stage and do a stereotypically racist of a black man then that is racist but not because of me being blacked up its because of what im implying with my impression
In the context of the black and white minstrel show it was pretty racist.
(The most famous person who "blacked up" was actually black though.
But that's not to say the character he portrayed (water Mellon loving, uneducated, etc) wasn't racist.
Re golliewogs my daughter has one. It's the one I had as a child, a free gift from the marmilade people (robertsons).