Now that I have had a little time to "gain perspective", I apologize for the innappropriate comment.
RCM may still be a good source for whatever SHO part you may need. If he dosent have it, he may lead you to who does.
Think of it like a trip to wall-mart. Asking a clerk where the buttermilk is, he says, "try grocery". When you get to grocery, you ask another clerk, and she says, "try dairy".
If it is a part that is no longer available, Try some of the used parts people on the forum. Many people have parts cars.
Now, on to your question. In all the research and work I've done on my SHOs, I'll have to admit that I have never taken out a cam or replaced a cam seal or touched the cam sensor (stay tuned though). I have never heard mention of a gasket or seal for the cam sensor. I have only heard of cam seals. I have a thorough (albiet, non-tacit) understanding of what cam seals are and how to replace them. The 3.2 I have on a stand in the garage will need all 3 before I install it.
If there is such a thing as a CPS Seal, then it probably either comes with a new sensor, or you can make one out of gasket material or it's a standard sized o-ring.
Have you removed the faulty part? A picture says a thousand words. I know you probably would like a replacement before you take apart your car. A lot of times, I have found that to not be possible.
By the way, do you know where the cottage cheese is?
It's an adventure for some of us, too. Were not ALL tour guides, but willing to help just the same.