412 Fuel Burn
Huey,
I would use a slightly higher figure of 765 lbs/hr at 75/75 Mast torque with a TAS depending on aircraft configuration - specifically float fit.
Apical floats 110 kts
Standard Bell Floats - 115 kts
No floats - 120 kts
I once flew an HP with tricycle wheel gear which used to bat along at 130kts plus but don't think there are any left flying!
Like you said - use Megan's figures and do the Math.
I still believe beeping back to 97% NR helps even though Bell have an undisclosed problem with that!
Trog