Hello Roland
I appreciate you looking for me. That is the number, and it does come up on cubcadetspares.co.uk, or at least it does if you access it via a Google search.
http://www.cubcadetspares.co.uk/gard...b51cj603-2006/
or
http://www.cubcadetspares.co.uk/gard...b51cj603-2007/
Picture is attached to confirm number. If I look in on their drawings, it shows an arrangement as per the next attached picture, which is different to mine. They show a single wide angle bracket, bolted directly to the top of the PTO case.
Thanks
Sutty