Without seeing the damage in person it's impossible to recommend a correct repair since the damage may exceed what is shared online and in photos and only tapping and close inspection
of the damage and hull
structures by an expert might determine if other stress cracks or problems have been introduced in association with the delamination
of the tabbing that you see. If the issue is limited to the delamination
that you see then the repair will at least include cleaning
and grinding the area in preparation of applying epoxy
and some combination of fillers and/or new glass layup
It may be that simply adhering the stringers to the hull with the current
tabbing is possible and sufficient through cleaning
tabbing and hull and injecting thickened epoxy
between the two. It may be necessary to remove all of the tabbing and start over or to supplement the tabbing with more layup
. Care must be taken to avoid introducing hard spots in an area that may need to flex as the boat works.
A big question is why did this delamination occur? Was it a one time incident like a hard grounding or dock
run-in? Was it caused by a mistake in construction that caused a weak bond? Did it happen as a result of too much hull flex caused by a problem in a different location and separate from these stringers? Another part of the repair will also included determining why the delamination occurred so that you can fix the source of the problem and not simply patch things up which could cause other problems etc. etc.
I hope those thoughts from an amateur boat restorer help. Good luck getting to the bottom of the problem and repair and feel free to keep us up to date. With more information (and perhaps without) you should get some good information from the many experts on this site.