My 1883 Colt 10 gauge has a very slight gap in the top half between barrels and breech face. From the middle on down it is tight. It has been this way since it has been in my possession and shows signs of peening marks by an amateur gunsmith in an attempt to put it on face.

I have tried some thin metal shims on the hook to no avail...still shows a slight gap at top.

Would you recommend sending it off to be put back on face? And if so, I would really appreciate suggestions on where to ship it.