Looks to me like either the hole in your vignetting card was too large relative to the size of the card, and as a result the left edge of the shadow of the card fell very close to the left edge of the print, or else you had something in your darkroom that reflects stray light onto the print. Clearly not right, and it may take a little detective work to find the cause, but it should be easily correctable.
I have an image of my wife and sons in my office made using a circular vignette, matte paper, hand colored. Very classic - very nice.