I have a 1974 Yamaha 650 XS that has been sitting for about 20 yrs. I am trying to separate the front fork tubes without damaging them so I can have them restored but I am having an issue getting them separated.

Hi.
my sister had one of these about 15 years ago.
if i remember correctly, when you have removed the wheel spindle and the caps for the spindle, you will find a bolt going up from the bottom of the tube. remove this bolt. then remove the spring cover from the top of the fork, and remove the spring. then lift up the dust cover on top of the bottom tube and remove the circlip underneath the cover. the only thing holding the upper and lower tubes together at this point is the oil seal under the circlip. just secure one tube, and slide the other sharply in and out a few times and they should separate quite easily. hope this helps

Assuming you have slackened off the fork top nut before removing the fork from the bike,and you have removed the screw in the fork lower, this secures the damper into the fork, next you will have removed the dust cover and seal retaining clip from the top of the leg, undo the fork top nut completly and remove the spring noteing which end of the spring is at the top, for replacment purposes.
Next fasten the lower of the fork into a vice on the flat ( not tubular surface of the fork leg) push the stancion all the way down to the bottom of the leg, then pull up sharply, repeating this in/out action to hammer out the seal from the leg until the seal/ bushes/ and washer have come out, this mat take some quick action movments to remove or separate the leg, forks which have not been appart in some time may need some heat on the fork seal. ARea of the lower leg