Did you ever think Half-Life was way too easy? Hard-Life corrects that issue.
The MP5 view model is something I spent a while on. It is an important weapon that you spend a lot of time with in the game, and I wanted to make sure it looked and felt great, while not jumping too far from Valve's designs. This is simply the EoD version of the MP5 with additional fixes to make some more parts pop.
This might seem trivial, but I unified all the arms/hands between the view models and patched up the weapons where they had holes. I also toned down the cartoonish barrel expansion they had to make it seem more like you're pointing the weapon away from yourself and toward the enemy!
That looks like the HL1 Alpha/Beta MP5 View model.