Fed 5B Light leak?

[Carriage]

I noticed some odd yellow marks on a number of frames in my most recent roll through my Fed


APUG reckons they're light leaks but if you disagree let me know. They all appear in roughly the same spot but some are bigger than others. Assuming they are, I'm trying to hunt down and potentially fix the issue. I've noticed that the shutter is wrinkled a bit when cocked on the upper edge

Could this be the issue? Is there something else common with Fed 5s that could be the cause?

 

[kotokot21]

It seems that your curtains are damaged by sun. The camera was left in the sun without a lens cap and the sunlight has slightly burnt the curtains.
Check the curtains with the shutter cocked with a flashlight — with the lens off, of course. If the curtains aren't light-tight you can repair them yourself.