jtr,
we also had some discussions about power/thrust conversion. The interesting and somehow irritating fact is that a jet engine produces maximum thrust ( full rated T.O.) while at zero speed, thus has NO power in means of physics; while it accelerates the thrust is decreasing, but the power equivalent is increasing, and there are formulas to calculate the power needed to sustain a certain speed.
With all the factors supplied for a certain engine type You can figure out a quite accurate conversion rule, e.g. for the CFM 56 engine it is something like fuel flow (kgs/h) x 4,3 = Horsepower equivalent; but as said, this number only applies to this engine. Older engines with a much worse fuel efficiency need a smaller number to convert.
Hope it helps