Is this a Patchett sling?

[Brit plumber]

In my very humble it's an ordinary Sterling sling that's been 'enhanced' with an extra clip and spurious WWII markings. I recall some appearing on eBay 2-3 years ago - IIRC they were being sold as Bren slings.

It's not had a clip added as far as I can see, I've seen how it's been done with others and this doesn't show any signs of that. The other thing I can say is that it's never been on ebay as lets say it came direct from source.