The NOD booklet/pamphlet dated 1959, issued to Naval Armaments Depots was pretty basic and written in usual stuffy Naval type language. It did mention to Ordnance Officers that the Lanchester would be the mainstay of the Royal Navy due to its availability within the service and all that stuff. So presumably the Navy would not adopt the Sten Gun.
In an effort to standardise the Lanchesters across the board it was suggested to Ordnance Officers that no standard Lanchesters be utilised in future ship disposals. From this I read it to mean that where ships were due to be sold as a complete unit, then the SMG's required to complete the ships equipment should be serviceable but of the non standard type*. The variables likely to be encountered were the obsolete Mk1 and another 'troublesome' variant with a pressed magazine housing that was prone to looseness. The only sight to remain in service was the standard mulit aperture variation ( no...., it's a twin flip-overleaf surely?). So the adjustable sight shown on Vinces was deemed non-standard. They also mentioned composite trigger housings - which I presume to mean the later welded-on trigger mech housings.
No time or opportunity to copy the pamphlet but I did take rough notes. These later Lanchesters were pretty much what we encountered from the Aust, NZand RN in the Base Workshops. They all seemed to be the later all-welded detail with flip-over sights and heavy cast mag housings. Never noticed a true Mk1 type. Mind you, at the time - late 60's - I didn't know a Mk1 existed! Some of the butt/fore-ends were dire quality but easily patched
Someone else must have one or two.
* The 2x Lanchesters shown by Vince and Claven2, with the tangent sights are the later non-standard type which would seem to indicate they versions sold off or otherwise disposed of early on, while the fixed flip-over sight type remained in Naval service