Actually all that stuff was intended for the fork as well as the frame if needed. You need to saddle the bent part of any tube between to resting cauls and then push down between with the needed force. To do this you need two surfaces be they walls or floor and ceiling or a big frame similar to a bearing press you can see at many automotive supply stores that specialize in tools. SOMETHING needs to contain the force you need to straighten the tubes. The floor and beam was the easiest to find.... normally...

If you insist on having at it then you can TRY making a frame to contain the pressures. Single right and left 2x6's with overlapping double 2x6's top and bottom with the verticals sandwhiched between. Glue and screw and allow to dry overnight. Make it up to be 3 feet wide by 5 feet tall. That can be your frame to contain the forces used for the straightening. A couple of more 2 to 3 foot 2x4's just screwed to the outsides will act as feet to hold it vertical. That way you can unscrew the legs and store the frame for "next time"... You'll still need scraps to form U saddles into to support the tubes while pushing on them. At NO time should you push on a tube with a flat surface or you seriously risk it kinking the tube.

By the time you get all this and put it together so that you can straighten the parts it may be easier to just write it off and shop for something used that is similar. Or take this opportunity to upgrade. We're talking about a lot of work and fussing around here with no guarantee of success coming out the other end. You may fix up a lot of this only to find something that can't be worked on.