The MD and Durham are two separate vehicles, you'd have to get the Mod Authors permission and knowledge of modding to add the Durham to the MD.
please, update to the Durham to make this real and not an edit (had to do a streamable upload because can't post images directly)
Given that the MD-Series is basically the Durham but more refined and versatile, I doubt this mod will get any major updates soon. Apart from fixes to game-breaking bugs, that is.
I really enjoy the Durham. It really has its own personality compared to the MD Series. And it was always cheaper, and have interesting engine choices.
Given the mod author has his own life, don't expect any updates anytime soon... The MD Series is a good replacement. That said, the Durham isn't bad, but the MD fills the space quite well.