Im working on the fork tubes on my boys rm80 tonight. Same thing as yours except his are 35 years old. Its usually the clear coat on the tubes that protects the alloy. I brushed his with some paint stripper and it just peeled away. Only left it on a few seconds and washed it straight off. Depending on how bad the alloy is, a very light sand with fine wet and dry or 0000 wire wool and then alloy polish should bring them up. Then, up to you but you can clear coat them again. I am just leaving the boys fork legs polished. Dont quote me on yours... test a small inconspicuous spot to see if you have clear coat and to see how easily it comes off.
Cheers,
Alex