I think the inner rear wheel arches on 67 are the same as on 68+ beetles, only the bumpermount itself is a one-year-only part.
I repaired my inner wheel arch with a 68+ part and a 67 bumper bracket an the parts lookes exactly the same as the rusted stuff on my car. At some point after 67 VW changed the style of the weld nuts for the fenders, so if you want to be 100% correct you need to take care oft this detail.
So you didn't have to make any modifications or anything? And which brand of repair panels did you end up using?