@jamal
Mine are FZR250 and CG125, and I want to add new fork oil in them both for better performance. However, I have to begin with the project yet, need some free time.
Now that I see that its not easy to find fork oil, I'll have to think whether to go for the task or not. Besides, there are other ways too. You can use automobile automatic transmission fluid (ATF) for fork oil. ATF was commonly used in the 1980s and actually recommended by some manufactures. It is normally about 7.5wt. If you use ATF in your forks, you should add 20-30cc of transmission sealer if available, the sealer lubes the fork seals. ATF does not have the anti-corrosion additivites that fork oil has so you should probably change it every 5,000 miles. I believe that the ATF oil would work fine for you if forks on your bike are not USD.
What bike are you riding and how much the seals cost you?