I had a wide choice of engines at Martin Yates (Lancaster), we ended up with an RNLI contract exchange 40, these have now all gone, so I'm told, and the new batch are 50 Hp, these will be available in a few months. Not sure what application but this was information this particular Mariner agent gave me. I imagine the forum member that works for Barrus may be able to shed light on this.
With the impending ban on Windermere I am sure there will be an abundance of engines (and boats) at the end of this season, perhaps many of the Northern based dealers would be worth contacting.