You shouldn't draw the numbers. If the clock is flat, it will fit in a quad where you just set the perspective with the four points. Masking the parts you don't want to map can be done with a picture of the real clock taken from front, that you could convert to a black and white image in Photoshop or other image editing software, then importing this image in MadMapper and use it in a quad at the exact same position with Blending Mode "Multiply". That's the easiest way I think. Drawing the contours of all the elements you want to draw to or mask is too long.