The one for my RRS was purchased from M and P’s in Swansea. Not sure how much I paid but I would have compared from other sources. Best of luck with the search.
I have use Electrex world regulators on many bikes and never had a failure so worth a look https://www.electrexworld.co.uk/
I found the SUN regrec's to work well on older stuff ( non injection) as a replacement. Don't forget to check over the fuel pump relay. Any good? https://www.ebay.co.uk/itm/20447469...RfBCHLTSky&var=&widget_ver=artemis&media=COPY https://www.ebay.co.uk/itm/27590691...RfBCHLTSky&var=&widget_ver=artemis&media=COPY
New one fitted and a nice steady voltage reading I will take it for a run later, any excuse for a ride out