This tractor, and equipment was sold once on craigs list for $1800, with a 5X8 trailer to haul it on. Then listed for $2500 minus the 5X8, now listed for barter. I looked at it. G'boro only about an hour from me. I walked away.
The Seller has created a very poor listing in every sense. I highly doubt that this tractor has a hydraulic deck on it.
However...that's not what you asked.
Yes... it is possible to make a hydraulic deck but it is not an inexpensive proposition. Aside from the fabrication time, you will need a motor, coupler, motor mount, hoses, quick couplers, a motor control valve and various hydraulic fittings.