Mine is a No 1 14 1/2 inches and the bun looks lower and somehow neater than that particular No 13. Is that a post war Norris? There is also about a 1/2 inch overlap of the sole at toe and heel. The lower part of the bun meets the first upward curve from the toe, I will try and sort a pic out.
Spiers planes look better still but then you are building a one off special that will suit you so get sketching .
Reading this on the phone yesterday - I had a buck labeled No 1 17 1/2 inch panel smoother years ago. Inexpensive because someone had dropped it and reglued the handle and reshaped the bun. Overall, it's a more refined plane - steel sides. The no 13 is casted and a little more crude and bulky.
A not-much-better picture of the no 13. the style of the lever cap screw may date it.
it's difficult to find a picture of another one the same length.
the smoother (no 13) is even a little less neatly made, but is a really nice working plane. this plane's proportions are also nice in use, but it could've stood losing a pound or a pound and a half in the casting and would be a better daily user. Which is what I intend to do if I ever copy it - refine the lines and level of finish just a little, make the wood a little less bulky and do it in a 1/8" thick side and 3/16th sole instead of whatever it is.
(just measured, 0.42" thick sole at the front and back, but machined or casted a little thinner in the middle. Still a tub. would impress people at a woodworking show on easy wood because there would be little feel of the actual planing - which seems to delight beginners).
The smoother version in 2 1/4" width isn't really overweight at all and doesn't have the same effect while using.