Tom,
I'm having some trouble following you, but I think you are making a mining light using a conventional bulb and want to try using LEDs.
While there are no single LEDs available to you, I assume 5 mm white LEDs as commonly exported through Hong Kong are? Based on your light output needs, you'll need 16 to 20 of them probably, each driven to 25 mA or so (a bit less total than you're now using, but not much).
I'd suggest groups in parallel sharing common drive. This would also allow you various levels by lighting up more or less groups as needed. Becuase Li-ion cells are flat in discharge, resistors should work fine.
Am I on the right track?
TIA
Doug Owen