Hi..welcome to the forum, and thanks for showing an interest in the hobby. I admire your courage and enthusiasm
Weeeell..there is..actually...a reason why we see so FEW of these machines out there...models of walking excavators...
'In the meantime I'm looking for scrap metal parts'? Sorry, no offense, I do not know if you are 12 years old, or a grown up person, and I don't wish to ruin your enthusiasm at all, rather try to avoid you from ruin your own enthusiasm of the hobby at an too early stage...; what about start out with a bit less complicated project rather than a model of one of the most advanced hydraulic excavators know in the history of the Mother Earth..?