They are worth what someone is willing to pay for them. Now that I stated the obvious...
Strip the line off them and load them up with your favorite flavor of line and go fishing. I wouldnt hurt to check the lubrication and make sure its not all dried up, thats a long time to be sitting but I bet they will be fine.
Those are good reels, the weakness is the galvanic corosion between the chrome plated brass and aluminum. If you wanted you could swap out the frames with Tiburon or Accurate aluminum frames if you can find some.
Tha drags in some of the old International reels were asbestos, I am not sure when they changed to HT-100 but the drags should be fine if they havent been used. The real advantage to the HT-100 and Duradrags is they dont get slick or jerkey when wet.
Good luck.
Brett