I reworked timing about 4 years ago and replaced a cracked timing cover with one I picked up on E-bay.
Picture and description matched what I needed but what I received was a bit more cleaned up and had 2 Freeze Plug Type seals removed.
Ports may be to accommodate front facing VVT valves vs the top mount I have.

Long story short, I ended up installing the cover and using a pair of neoprene compression plugs that have done the job.

However this weekend I replaced valve cover gaskets and noticed that the exposed interior neoprene was swelling and getting soft. I went ahead and swapped in a new set but would really like to get something more compatible.

I used the neoprene due to not being able to find a Freeze Plug or compatible seal anywhere near that size locally. I've reviewed SNG Barratt's online catalog for 2001 cars and the only seal they list is the gasket.

I'm wondering if there is even and OEM spec for a part to seal ports that were for another purpose altogether.

Any ideas or direction on where to look are appreciated.

 

If I were you, I'd look for those forward facing VVT's from a
97' - 98' XK8 or a 98' XJ8
(Both naturally aspirated) engine and use that to plug the hole. I know those forward facing VVT's have a real thin, square cut
(I believe) o ring. Of course it'll just be there to prevent an oil leak. If you do go that route, I'd silicone the o rings before installing them.

 

The top set VVT's are an assembly secured to the head under the valve cover, probably the same set up as the front set short of connector location. Not much room under the valve cover for another one. And swapping them out for the '98 leaves me the issue of what to do with ports on the valve covers.

 

It appears that the ports are definitely for the front mount VVT. I checked out Ebay and found a few - Not sure how they were set up but they definitely show an exterior bolt mount and don't appear to be much deeper than the compression plugs I'm using. I will say that 50.00 a piece is a little steep just to cap the hole. I may template the mounting rim and make up a couple surface plates and gasket them using some oil resistant gasket compound. Appreciate the nudge in the right direction though.

 

I would definitely agree that $100 is high for 2 plugs. Are you located in the states?? There is a very small chance that I have those forward facing VVT's.