Look at the last of the pics in the listing - that bowl's been pretty well abused over the years, whether by smokers or by restorers trying to clean it up. It wouldn't surprise me if it's topped off already - notice the heavy blackening at the outside edge at 6-7 o'clock in the last pic. The oversized dot on the stem is annoying, but the replacement stemwork itself looks solid.
It could still be a right decent smoker, but I don't think I'd pay much more than the minimum bid for it myself. And even if you bid on it, I wouldn't get attached to it until I had it in hand and made sure I didn't want to return it.
My guess is that the fact of it being a `38 patent will drive up the price beyond what I'd consider it to be worth. But I'm certainly no Dunhill expert - I just own a couple and watch estate listings occasionally.