No. Hydraulics were never offered on the 70 or 60 lawn tractors. It could have easily been done though, and I'm not sure why John Deere didn't give it consideration. It would have been nice to have the hydraulic option for those of us that use our tractors primarily just for plowing snow. I'd be interested to see what you come up with when you're done.
On another note, I know that the model 70 was once thought about being offered as part of the Patio Series line up, but was eventually canned. Deere was going to offer the fifth model, but since the 110, 112, 120, and 140 weren't taking off like they had hoped, they decided to just sell off what they had in stock of the bigger models, and not offer another model. However, even though the 70 tractors weren't offered in dogwood white, some of the attachments were. I don't have any personally, but I have seen white 32 snowthrowers, 40 blades, and 34 mower decks at various shows already. Some collectors look for these attachments, as there are considered somewhat rare, and sometimes can be very pricey. Myself though, never really got into collecting the patio series line up, so these white attachments just don't interest me. Personally, I think the patio series is way over rated, and just can't justify spending more for a colored seat or hood, then you would just for the tractor alone. Just me two cents worth!