No Mike, its what I told you about.
Take a DX 3 lens reflector, and bore it out with a 12mm drill, and you will get 3 P7s in, but you will have to take a shave off one of the 'flanges' of the 21mm heatsink base of all 3. Then they will fit.
I have only done this tonight, so have not yet fired it up.
However, the intention is to wire 2 of them in series and drive with 3 X MR16 drivers in parallel. I will have to fine tune by changing the resistor of at least one of them. The third emitter will run of a KD 12V - max, medium, low driver mode reg board with a simple isolating relay circuit same as the UniStar to bring all 3 on line from SW2. ( I did try diodes but NG)

I hope to get a lamp up by next week and will probably run my comparison test off the car battery. I am expecting a voltage drop when I try to run it off LiIons and my possible solution to this is to go to a 16V array of cells and a MOSFET voltage regulater in the battery lid, together with a LCD voltmeter.
People who use my lamps will expect to be the centre of attraction underground and I cant let them down.
All in good fun.

---