This is the original:
And this is my remake, keeping the pneumatic functions, and the double function of the HOG, for steering and for upper excavator body rotation, like all 90's technic set rebuild the main challenge is to "translate" the proportions of technic bricks (6:5) to liftarm (1:1) another detail you will notice is the colour change, from red to orange in order to give an actual look to the model.
The result is a not very elaborated but very playable excavator ( it took me less than tree hours to build)