The numbers are a bit soft, but don't forget most of them would have been thwacked in, often by hand, before the parts were heat treated and blued. (The reason so many bits have the serial number is because of the massive amount of hand fitting, meaning you don't want to mix things up, so I assume the serials would go on fairly early.) So, with the goal being to recreate the filming prop rather than the in-character blaster, the soft edges and paint-filling effect of your numbers is probably adding to the final result. In photos, at least, they sure look like stamped metal to me!