Ant then removed it!
I bought a split screen focussing screen from ebay, thinking it would help with focussing manual lenses. It was easy enough to fit.
And then I removed it and refitted the original. Why?
I lost spot metering, which to me is one of the major benefits of the 510. Don't get me wrong, it worked, focussing was much easier, but it wasn't worth losing spot metering for.
Dave