I think the tabs are held on by "corvett glue" A strong bonder used to attach stuff-I think I saw it on a vidio making jet skis to hole the motor mounts ,etc in the hull. I would check with a body shop. There are some epoxys with a lot more strength then just fibergalss resin.
I need to take a pic of a fender repair (stick together) done on the road with no sanding just ether as a cleaner,It was supposed to be temporary -but we all know how that goes,I was trying to start an operation and not feeling up to par,so it was not a high priority at the time. I post it when deb gets the camer back.You will laugh but the fact is it held. The strongest epoxys I have seen are Marine tex and then JB weld -PC7 my my there are a lot to chose from but Marine tex is my favorite (pricy but strong) it has proven its self to me over & over.
The "shoddy" patch was done in nov 2002 on the ide of the road -with no sand paper ,just a rag & some ether to clean it with. The white is the Marine tex (there is soam on the inside & outside of the crack),note it still looks clean -not effected by UV rays. The yellow on the uper part of the crack is just some epoxy I had in the truck. I allways carried marine tex in my truck. The repair is almost 8 years old and still has a good grip,I just pulled on the fender enough to flex it and it still held fine. The truck has been thru NYcity streets (rough as they come).Once we could only go 20MPH because of the shacking and pounding the road was giving us.My fenders are rough on the inside and need a lot of work. Also that all the marine tex I had with me at the time.
I think this at least gives testimony to a great product!