They're not the best of forks as drag all the way internally with no bush so everything has to be aligned to work as good as possible. At work we found a problem with every crash damaged Twin of that era--& there were lots of crash bikes back then--. We found the lower alloy slider got bent, so forks jammed & could revolve the bottom & be obvious to see. Could take an eyeball line off the damper bolt in the bottom while revolving. No reliable way of fixing that other than replacement. Only mentioning this as was from the same era as the RT2 & very similar lower sliders. Other main thing i'd try is individually revolving the forks without wheel or guard although guard would flex in place. Just loosen the clamp bolts on the triples & turn the top fork cap. Any fork tube bend will be plain to see. On second thoughts you could leave it assembled sitting on a box but neutrally touching the floor lightly with front wheel. Loosen the axle clamp on the lower right & turn top cap with triples loosened. If its bent or bent on both but not by much, you could find a less stressed neutral spot maybe with both pointing back equally so steering is straight. Then tighten everything & give it a go. Sorry about the essay.

How do they feel individually when empty of oil & springs, that'd be a good test. No caps either or you'll feel air you're compressing. Not sure if its possible but maybe you could get the slider honed to take a gnats whisker out to improve it. Still be interesting to revolve the forks or if you have them out of the bike just hold the slider in one hand on the bench & revolve the stanchion tube to see how straight they really are--& hope they are--straight.