PurdeyB, I think you would be correct about it being Hunt & Wrigley. As you say it can't be opposite as it's the pub but I suppose it could be a corner at the other end, one of which would be unrecognisable today but unlikely as away from the main street. I will have a look for a date stone.
I too was wondering about the post and "post offices". Given that stamps were introduced in the 1840s it presumably became a more generally accessible service. And as you say rail. The post probably switched from coaches to rail at some point in the first half of the 19th century. I was also wondering if earlier "post offices" were actually in the coaching houses.
Gillian F's ancestor wasn't a Post Master in 1841 as far as we know. Maybe it was a new post. Pure speculation though, next will have to read a history of the Post Office. That's the thing with this hobby, there's always new avenues to explore.