Any ideas please.

I found a box of 10x12 Kodak paper, it must be at least 20 years old and to my surprise and delight it is still giving a full range of tones from deepest black to clean whites! Itís a really nice paper and there is a hundred sheets. It is grade 3 Hard and with my Durst DA900 condensing enlarger it prints a little harder than I like for some negs. I tried removing the condenser but the exposure time was far too long, I tried placing a piece of tracing paper between the condenser and the Lens bellows to act as a diffuser but this too made life hard. Can any one suggest the best material to use for a diffuser or any other suggestions? I would really like to use this paper rather than throw it in the skip. Any suggestions would be appreciated.
Thanks in advance.