The Old'e English Shaving Shop sells old-style English shaving brushes, razors, creams and after-shave lotions. While they do have a small shop (in Maitland, just outside of Cape Town), they also have an online store and a genuine old-style barber shop, Mr Cobb's, at the V&A Waterfront.
I'm not sure how comfortable you guys are with having a stranger toy with a cut-throat near your neckline... but I'm not convinced that I'm quite ready for the experience. I mean, what if the barber has some kind of alter-ego Mr Hyde-like personality? Scary stuff man, scary stuff!