http://www.ebay.com.au/itm/Williames-Williams-Wildcat-and-Hydraulic-Slasher-Vintage-Tracto/322039571722?hash=item4afb0de50a:g:xuIAAOSwh-1W5k9z

This one looks to be in reasonable order. Note that the front ram is missing and listed as leaking. Most hydraulics places are loath to replace ram seals these days and when they do the cost is pretty much the same as a new ram. Expect to pay around $350 for a new ram, more if you can’t reuse the old hoses and fittings,