How about the repacement
"Dwarvish war machine" 4 6 1 9 Break Tackle Breaks down 120K
Breaks down is the negative skill which causes the deathroller to be taken off when it is knocked down.
These devices don't gain skills, they are upgraded by their crews. Models may be modified to show the new skills (eg a big hand sticking up if yu were to gioive one catch
The deathroller is then a star player of this type