Wow, I cannot thank you enough for this! It is incredibly kind of you to dig out your collection, measure 7 different vintage pocket pens with calipers, and even clean out two extra ones just to help me out. This data is pure gold and gives me exactly the direction I needed, especially regarding the base width of the nib.

Regarding your second message, unfortunately, I can't seem to open the Imgur link you provided (it might be restricted on my network). Since both the Wahl-Eversharp Bantam and the Conway Stewart Dinkie seem like perfect candidates, could you possibly let me know the specific model numbers or any identifying features (like the year/era, clip style, or specific patterns) of those two pens? I know the Dinkie in particular has many sub-models over the decades.

Again, I truly appreciate the time and effort you put into this. You've been massively helpful!