Thx for feedback all,
Following positive coments from the forum, I went over to DMS for a ful P3 and well worth it. As you all noted, they are very helpful and let you watch and wander (as noted in "Do you trust them" post).
Added bonus was that despite the service invoice from seller, the diff oil clearly hadn't been changed. Now comfortable that I can press on with good oil all round !
Cheers
neil