May have some news about direct availability of these in the near future (a few factors dependant)...
I know you're a bit coy about promoting stuff on here, but I have a question: is this http://www.excellentstuff.co.uk/Oldham-Lamps/c-1-89/ the DL16?
Presumably the GL16 is the halogen version and the DL16 the LED version, both of which use the Li-Ion battery whereas the DT5 and DT6 are the LED headset suited for the T5 and T6 batteries respectively?
Apart from the manufacturer's website and this one, the majority of Google searched pop up with stuff in Durham - presuming that DL16 is a postcode somewhere round there...
Yes, thats the DL16
The D is the LED headset, the G is the halogen headset
The T5 and T6 part refer to the lead acid battery and the L16 is the LitiumIon battery.
batteries and headsets are interchangeable, I use a D headset on a T6 battery (giving me a DT6)
With the balck plastic battery tops you can use either lead acid or lithiumion battery, the fittings are the same.
In my humble opinion the DL16 is by far the finest underground lamp in the world, not the brightest perhaps but factor in battery duration and sheer indestructablity then its top rank.