didn't 69 have horizontal headlights and the 70 had the vertical headlights as part of the front fenders?
I wouldn't think it would work out perfect but maybe you could take the lower part of the front fenders and patch?
^You mean the marker lights? Then yes there is that difference. But the marker light assembly should come off the fender and be interchangeable with the other year.
Structurally they were identical and '70 just has a few cosmetic features. The only real difference in the fenders is that the '70's have those two emblems, mounted on the tips. Those emblems are bolted on, though holes punched in the fender. The '69 fender will not have those holes. But otherwise the dimensions should be the same.