In the process of beginning a crusade to refurbish my tired looking troops choices, I also set about upgrading one of my Chaos Contemptor Dreadnoughts. I'll probably get to work on the other one, but for now I'll be working on the one.
The dreadnought in its former condition

It's main change would is to its armament. It started off with a Heavy Conversion Beamer, Power Fist and Plasma Blaster. Nice weapons, but it seems not the best when combined. The blaster has an 18" range, and the Heavy Conversion beamer needs to be far away to be most effective. So in order to get the most use out of the Plasma Blaster (which is in-built and the hardest to remove anyway), I've re-armed the Contemptor with a Multi-Melta.

It was make with the Multi-Melta left over from my Jet-bike lord, with other spares and plasticard. to look similar to the official arm. It still needs some further details and cabling.
It has been magnetised with smaller, easier to install magnets, so I can swap it out for other potent weapons such as the butcher cannon, which I plan to make later on.

The trim is iconic to Chaos Marines, and it only seemed fitting to add some to this. It still needs some more details and rivets before it can be called finished.

I've also decided to add a havoc launcher. More guns is always a good thing, and its twin linked blast will be very handy if I'm stuck fighting hordes and not tanks. I was planning to use a Kromlech Zephyr missile launcher, but my club had none in stock, nor the Maxmini alternative.

They did however have these, Bronze pattern jump packs. And in a way to please any Orky Mek, I came up with a cunnin' plan. I've reversed the jump pack, and stuck hollow circles to the other side, where the exhausts would have gone, and hey presto, big death-spewing havoc launcher! I did fear that it would be too big, but feedback on the Facebook page convinced me it was suitable for the role. It looks suitably intimidating and functions. I am thinking about adding a few pointed ended inside the circles, to act as the missiles.