Special washer

[neilxjs]

I am looking for 2 of the special washers that fit between the front subframe "six shot" mounting bush and the body. The Jaguar part no. is C30370 but is no longer available. I was replacing the bushes and discovered that they were missing. Perhaps somebody would have two of these spare or alternatively could explain what is special about them. Any help would be appreciated.
Cheers