rear sight out of plumb

[Lumpy Grits]

CL, don't suppose the g'smith bumped the front-sight over to the side?

it does not appear so, I will check the plumb tomorrow and a good look at the front sight, I just might remove the rear site base, wipe clean, oil it and reinstall just to see what happens.

I am guessing everything is tightened down a little different than it was before it went into the shop

Could a shim have fallen out/lost when he removed the tang sight?
The smith didn't need to remove that sight, BTW.
If the sight is "square" to the bbl's top flat. Just move the front sight the get your "O" back.
Tell us how you ck the tang sight for sq.
Gary