Why is Lion Server not available in UK App Store

I am trying to upgrade my old Mac Mini (running Snow Leopard Server) to Lion + Server

When I try to install Lion, it reports Lion Server must be present before installation starts.

So I go App Store and in my purchases there is Lion Server. It reports 'Requires OS X 10.7'.

If I click on the link 'Requires OS X 10.7'. App Store takes me to Mountain Lion app.... Grrr....

If I click on OS X Lion Server (in my purchases) the App Store says. 'The item you've requested in not currently available in the UK Store'.

I see Lion Server on the US App Store but not the UK one.

Why is Lion Server removed from the UK App Store?