I bought some vehicles in a sorry state second hand from a friend that had bought them second hand himself and I converted two Leman Russes to Thunderers. A lot of work have been put into these to make them look as I wanted them to.
I used the dust filters that Forge world sell originally to the super heavies but one pack of these is enough to two regular vehicles with some converting.
One of the Thunders were given a Tyranid scull as trophy but I only painted it rather generic as I have heard that a friend of mine is about to change his Tyranid colour patterns so I will wait until I have seen his final colours before it will be completed.
Here are some Work In Progress giving some hint of the sorry state they were in when I got them.