Ok, so been in to Honda today and they don't show a superseded part number against the original part for my lude, so that would suggest this thing about there being a later part which is plastic with O-rings instead of the rubber part, is a fallacy???
The parts guys didn't know if this particular one was double ended from memory, but the parts diagram shows a double ended part and they believed you did have to remove the cam cover to change it, as we suspected.
I also did a search for an earlier post I remembered and Nafe had posted up a pic of the genuine Honda part
here
In other news (I've been meaning to post this for a while) The JDM doesn't leak and it seems a previous owner/mechanic found an alternative way to achieve that, without replacing the seal;

But hey, don't knock it - it works!!!
