Hey - am selling a Mission Workshop Monty. A few photos below. It's in great nick.
It's this: https://missionworkshop.com/products/the-monty-messenger-bag
There's one blemish - the stitching holding the velcro to one of the flaps was coming a little loose. It wasn't affecting the bag at all, but I've (crudely) reinforced it. See the pic. You might want to do a more elegant job than me with it.
I bought it a few weeks back (https://www.lfgss.com/conversations/352441/) but switching to a different bag.
I'm in N11. But also in town tomorrow (Friday). Will be around EC2Y at lunchtime. Pick up ideal, but can post if needed.