This is a strange one.
Al's noting that it's a Grp. 2 (I missed it---check the circle and enlarge/enhance... yup, it's a "2") definitely COULD be why the dot looks so disproportionately large. Have to be a hella small #2, though. I've only seen a few Grp 1s that were
that small.
And the goofy elbow-bent stem/shank fit in one pic does not show up in one of the others.
Meaning if that's some trick of the light---the stem is actually straight---
and the pipe is a Grp2-sized Group 1,
and the shank wasn't sanded to fit a rep but just buffed to hell, the stem COULD be original. The button looks right, anyway.
No doubt about the chamber having been over-reamed, though.
Bottom line: It's possible that the pipe IS worth a hundred bucks. No way to be sure until having it in hand, though. The photos are just too weirdly ambiguous.
I think you'll be surprised how small it is if that's a legit Dunhill stem & dot, though. Like a wee leprechaun peep. Probably 4.5 inches and 15 grams or so.
If you have the means, OP, please take some more pics when you receive the pipe. This is one of the better visual mysteries to come along in a while.