You may want to take a look at the technique I used here:

For PE I investigated the extension to full body texture conversion but the 'cut' of PE' uvs were too different from V4's to make the conversion via this route feasible.

I looked shortly at LaFemme's mapping the other day and I concluded the difference with V4 uv mapping is much smaller than it was for PE and in my opinion it could be made to work with results good enough for the average Poser project, especially if the result is to be in accordance with the Rendo TSO.

General topology ('skin cut') is the same for both figures, but location of seams is slightly different. Essentially you would need an extra copy of the V4 body texture with a mask to combine that with LF limbs. Accurate re-mapping the crotch area may be a challenge, but again how important is that for your puropse.

I do not have the time to work this out myself on any practical timescale so I gladly leave it for anyone interested.