This is obviously a UV & salt issue.
Up on Lake Ontario, you don't see this type of degradation in the clew straps.
What I wanted to do was re-visit an older post of mine for your benefit.
I noticed your leech line, where it is wrapped up in a few knots, etc.
The problem with the leech lines is that they stretch.
Ideally, what you want to do is set the leech line each time you unfurl, and then release it prior to furling.
This is all but impossible on the 49, because the boom is so high from the cockpit.
Plus, the Mickey Mouse jam cleat on the sail doesn't hold. That's why your end up tying knots & leaving it.
Unfortunately, leaving a tight leech line on a furled sail doesn't help it keep a good shape.
So, I invented a really neat way of dealing with this..
What you need to do us install a small cam cleat on the aluminum pulley block
See photo below
View attachment 67988
Now this gets real easy.
Once the sail is unfurled, you just grab the leech line, pull it downwards, and it's self- cleating. Pull it nice & taught, and watch how you get a beautiful shape in the sail leech.
Just before furling, grab the line, and snap it out of the cleat.
You can put a small loop in the end of the line,
And use my special-purpose-leech-tensioner-tool model LTT-101, also known as a short piece of coat hanger with a hook at the end.
You can make this yourself in 30 seconds, or if you are the US Govt., you can buy one for $73,500.
Guarantee once you have this setup, you will find your mainsail shake improves dramatically. Plus, less stretch on the leech.