I’m not sure about the lack of the Shelby patch, but it seems you have the right manufacturer as Bonham’s had one for auction at some point:
https://www.bonhams.com/auctions/24143/lot/6/
Here is another one that was claimed to be owned by Ken Miles(!):
https://www.carandclassic.co.uk/car/C905673
I swear I saw somewhere on the Internet recently that one of the original team jackets sold for $11,000 but of course I can’t find anything about it now.