Dahon Speed Folding Bike - Project/Spares or Repair

The seat post is jammed and there is a wedge in the lower frame that looks to have been used to push it up. The frame looks undamaged;

The saddle is begging to degrade;

Bottom bracket has play;

Rear brake seized at lever, front break lever works but not brakes;

Chain needs replacing and block rusty;

Gear changer is seized; 

Folding points and springs are rusty so will not currently fold.

Collection from West Reading RG30.

Thanks for looking