Any suggestions for hairline gap fix? (photos)

The area of concerns is amenable to a hair transplant without requiring many grafts.  What I will draw to your attention is the difficulty in creating density given the location that concerns you and the color contrast between your scalp and your dark hair.  You may need a secondary procedure to help increase the density.

If you are not losing hair and always had a gap on your hair line that bothered you, you can probably have a hair transplant with good results.  See a doctor.

Hair transplants to fill hairline gap without hair.That would be a better choice than having the area excised because of its shape and small size. See a very experienced hair transplant surgeon for the best results.   

Please consult a dermatologist who specializes in hair loss. Autoimmune causes need to be excluded before you proceed to hair transplants too quickly.There are a few things it could be, not just one. An up close examination with dermsocopy is needed to determine what is happening to these hairs and if there is any scarring in the area. If it's been stable hair transplantation could be a good option. I'd strongly suggest getting diagnosis from an experienced dermatologist specializing in hair loss before pursuing any surgical corrective options.

This can easily be fixed with a small FUT (strip) hair transplant procedure. A very small amount of grafts would be needed and the results will be very natural. A hair transplant should be undetectable when done by a skilled surgeon. 

This problem should have a simple solution in follicular unit hair transplants. One session is likely to be sufficient. 

This area can be fixed using hair transplant procedure. In the hands of a skilled hair tranplant surgeon it will look very natural.