The border point is quite a bit off the bridge centerline though; if you move it in mo.mo273 and mo.us059, I'll move it in ks.us059:
KS/MO http://www.openstreetmap.org/?lat=39.559412&lon=-95.113116
They moved that bridge south a few years back; looks like the HB is still using the old bridge location.
I don't know if it means anything, but despite the border running through the middle of the river, all the "Leaving Missouri" "Kansas Welcomes You" "Atchison: History, Mystery, Entertainment" etc. (I've been over that bridge a lot) signs are where the bridge touches land in Missouri; not sure if this would move the border point or not.
On a slightly unrelated note, the SWMorRd point in MO on both 59 and 273 can be cut; no one uses it without going to Atchison (if someone actually is, I'd be surprised).
