How large is a large joint of gammon?

Not many missions come up this far west in Hounslow (away from most GG'ers) and I jumped at the chance to deliver groceries to a gentleman who is self-isolating.

To my delight, there was a prearranged shopping list that I was given beforehand, and it meant I could do some research into exactly how big a "large joint" of gammon is meant to be (can you tell I've never had to guy gammon before?), as well as which was the best of the local supermarkets to acquire the items on the list.

With almost 2kg of gammon plus large quantities of milk in my backpack, I cycled to the gentleman's house, trying my best not to squash the bread.

Having survived the occasionally fierce heading and very dodgy trail routes that Google Maps gave me (fun with nettles), I dropped off the items by Mr F's door and was relieved to discover that I had chosen exactly what he would have bought for himself. We had a quick but lovely chat where he introduced me to a neighbour's cat. Reluctantly, after only 5 minutes of petting said cat, I got back on my bike to go home, pondering whether I should give gammon dinners a go soon.