The adapters are homemade from stuff that I found in the shed.
As mentioned, the ring itself is Tricoya. The retaining "collets" or backing segments are from some 1.5mm ply that was left over from a drag racer seat mould that I toyed with years ago.
The clips, which are perfect for this job, are actually greenhouse glazing clips, but it turned out that only the specific type that I prototyped with, would do the job. Finding the right ones again was tricky but I found them in Northumberland of all places!!
Pics are of my first prototype. "Production" ones work in exactly the same way but fit better and are minus the peripheral cutouts, which were a pre greenhouse clip idea.
Each kit contains an adapter, a 1.5mm ply retaining ring to cut into suitable segments to fit your lamp unit and 6 greenhouse clips.
Please note this a very trail run. any further production will require outlay for more materials and so might be a bit more than a fiver!... I'll see what the demand is.