Two pics of my 499 and 467 unrestored distributors, showing the stepped diameter at the top. The lower picture is one of yours - you can see why I questioned the appearance of a "no step" by the pic - it looks completely smooth as compared to the last one you posted beacause of the cap being installed. By diameter of the body, and the presence of the step, I'd say it's that much closer to believeable. The last angle you show looks totally different than your first examples (even though they were great shots), due to the cap being removed.
Note one other thing - the date stamping font size is slightly smaller on both of mine as compared to the part number stamp - the "9" is different on the 499 in shape in addition to size. Just an observation, If you're wondering about the color of the stamping, it's White Out correction fluid, added for contrast. Both distributor housings had to be soaked to remove the accumulated crud of centuries and expose the numbers. Should have taken "before" pics as well -