Can you solve the mystery Brighton shirt?

[Muttley]

As posted on main board:


My mate Vicky's boyfriend found this shirt in the rough by the 6th green at Benfield Valley golf course, and I've never seen it before!

Can't be the new kit as it's sponsored by skint, but very strange to say the least!

Can you tell me what kit this is? Has all the Errea tags and labels like other shirts.

 

[Insider]

I suspect it's an old prototype (perhaps from two years ago)which has probably been recently thrown out and somehow got from the waste disposal to Benfield Golf Club.