The D17 appears to be a nice looking old tractor but your description of the power director clutch causes me to have some concerns.
Itís not a matter of a simple adjustment shims must be properly removed and added to get proper clearance for the high and low part of the clutch..
Because of the Power director issues I personally would not want to pay $5800.
Iím thinking $3500-$4000 tops; for my money I wouldnít want to go over $3500
If the power director clutch needs work it could be $500-$2000 to fix it depending on what it needs. The tractor would need to be split which isnít a bad job.
Problem is once you get it apart you may find more trouble.
On the good side The D17 can have a 3pt made for it and a separate valve 2 or 3 spool open center valve with 1 one way spool (for the rear lift) and the other spool or spools can be 2 way.
This valve can be plumbed in to allow for 2 way hydraulics.
PS. Where does the hydraulics for the pump get its oil?
If its from a separate tank your ok but if its from the reservoir of the tractor maybe not so good because you cant add a spool to the current tractor hydraulics