What happened to my Leica M6's shutter curtain??

I just bought this M6TTL a few months ago from someone on another forum. Gave it a good look-over when I received it and didn't notice anything out of the ordinary. A week or two ago though, I noticed some weird indentations on the back of the shutter curtain when I was loading some film. Didn't think too much of it other than I might have been a little too rough loading a roll (this is my first Leica and have some problems loading the first couple rolls).

Yesterday I took the lens off for the first time since I bought it and noticed two small 'globs' on the shutter curtain. They're in the same position as the indentations on the rear side of the curtain. Looks like whatever this damage is happened on the front of the curtain and made it's way through the back.

Checked some recent negatives I got back the other day and didn't notice anything unusual in the images, so it looks like the curtain is still good. Just have no idea what this is or how it got there. I remember reading here a few weeks ago someone reported burning a hole through their Leica's shutter curtain by leaving the cap off, so I'm wondering if that might have been what happened:

I have seen Leica curtains with holes repair. Usually they are not this far from the center.
If it works now, not a big deal. Get flashlight and get into absolutely dark room, place flashlight light behind lens mount, look from the opposite side very closely. If no light comes, it is good for sure. In worst case, if you are in USA. It is easy to get replaced. And not terribly expensive.

maybe it was burned by the sun? This thread discusses the issue (there was a url link here which no longer exists)

Sounds like it's time for a shutter replacement. L

Sloppy repair on a holed curtain. If it doesn't leak i wouldn't let it bother me.
How'd it get there? Ignorance, careless handling, burnt? The holes look too large to have been burns,
more like something stuck it. Why?.....

I've repaired several holed curtains the same way, but the repair should have bee barely noticeable.

Replacing the curtains of a Leica is a quick job if you have a capable tech.

If everything is working OK, why worry about it? It's surely shutter damage that someone patched up, and if it shows no issues on your negs, you're good to go. Unless of course you have recourse to get a partial return toward an eventual shutter curtain replacement, or a full refund on the camera by way of a return. If those options are not available to you, just shoot it.

As your camera is over 20 years old anyway, why not get a CLA done and replace the shutter at the same time?