IMHO definitely want to disassemble em and look at the bottom of the lower stanchions. IF there was ever even a tiny leak past the fork seals (and there are exactly zero old bikes with old seals that haven't leaked), you will find a disgusting thick blackish LaBrea Tar pits sort of gaaacky mess down there. So when you leave that in place and put in nice fresh fork oil, the plunging action of your forks causes it to stir up and mix with that crap and you have just ruined your nice new fork oil. You may even have disturbed particles big enough to clot the damping tube holes which messes up the proper function of one or both fork legs. To me, having the forks work correctly, where their main job is keeping the tire's contact patch connected with the tarmac as much as possible, is (kind of) a critical mission and I wanna make certain they are able to do that correctly.
Disassemble, clean meticulously, and be sure to clean the inside walls of both tubes -- I use a cheap shotgun cleaning kit I have with patches soaked in acetone for this). Check your upper tubes for straightness by rolling them along a glass table top or similar true flat surface. they both must be perfectly round/linear cylinders or they need to be replaced ($120 or so for the set). If you are keeping the old ones, then check the surface of your upper tubes where they pass the fork seal through their full range of movement with your finest, most gentle fingertip touch. IF there is pitting/scratches, those sharps will cut your new fork seal and you will have leaks (which create probs BOTH ways -- water can get in when washing the bike/riding in rain, and of course oil seeps out). IF you have those burrs, you can remove them: you can microfile or use fine grit emery cloth (400plus) to smooth down the high points, and fill any pits with the world's thinnest layer of JBweld (acetone or denatured alc first to prep surface). IF these dings/cuts are deep enough to have gouged in past the chrome layer, you probably wanna replace the tube.
After it cures, work it with ever increasing grits of emery cloth (wetsanding very gently, using the curve as a guide - DON'T PRESS HARD down on the spot or you will create a "flat" that is just as bad as the highspot you're trying to remove). I wrap a thin loop of the emery cloth around the forkleg and work it that way, slowly. Keep going till you get up to 1500 or even 2000 which feels basically like plain paper. Do the feel test again for roundness and smoothness at your repair.
Fun tip: I found that I can pick up far finer aberrations if I run my pinky tip over the metal with my EYES CLOSED and silence in the garage. It focuses my attention on the tiniest of things there. IF your manly fingers are too rough, get someone with tender fingertips. I once asked my daughter (who doesn't have guitarist/mechanic fingers) to check a fork tube. She found things I literally couldn't feel, but could SEE with a strong magnifying glass when she pointed them out. I fixed 'em :-) Anyway, when it's smoother than smooth, reassemble with fresh oem copper washers at the 8mm lower fork oil control bolts and the m6 drain bolts and new fork seals PROPERLY INSTALLED. And yes, this takes a bit of time, but once it is done, at least this will be one system on your bike about which you needn't worry for quite a long time.
