Cheers guys, yes a side gear is available though less common, it was the standard RNLI Y Class fitting but I understand it was a 'civilian' option too, otherwise spec is exactly the same. As mentioned the Merc is the same but I'd just prefer a Mariner as it's destined For a Y.
I've got the chance for a 2001 model at around £875 but it's a little cosmetically challenged paint wise on the cowl.
 Bejesus, just seen Bridgers price!?!! OK it's a 2008 and I'm fully aware of the used 9.8 and 15 2 smoke prices but £2k?! they're having a laugh
There are plenty of 15's I've seen going for 1/2 to 1/3 that price (obvously a little older but only by a few years) and you still get the real bargains, a Mariner 15 2000s at £350 was advertised Saturday, too far away for me sadly.