Fabricate a feedhorn mount to keep the current position then bolt an Inverto Black pro LNB to that feedhorn. You will have a awesome KU system!
My plan was to rig up a geosat pll lnb there, but you know your stuff... Can you break that down for me a lil more, I can't quite picture that. I may be mistaken but that LNB pictured is a C band is it not?