Classicalgas,
I converted a couple of heads for someone a year or so ago. The stock TD020 glow head has enough meat to simply cut the taper and threads in it and you are away. I never heard how they ran but I imagine it would be very similar to the nelson, perhaps a little better due to more flexibilty in the combustion chamber shapes you can make.
What advantage is there in running extra proplyene oxide in the fuel?

Stefan