Hatch cover

I bought an old boat (1140) and it has one hatch cover missing. I dunno what brand it is as there is nothing written on it other than "Open" and Close". It is not a Ronstan, Riley or Nairn. The thread OD is about 104.5mm and the lid OD is about 113mm.

I need one cover before I can sail the boat. I would like to get three so that I have a couple of spares.

Can anyone help?

Thanks,
Greg.

Photo here...
http://i.cubeupload.com/YmJVrY.gif

Just guessing, but it could be one of the home brand type ones, that are sold by Whitworths, Jolly Roger, BLA etc. There used to be alot of them around a few years back, not sure if they are still around.

Old style Nacra cover

can by hole hatch from bcf for 15 dollars