You are far better just downloading the original from dell and using andyp's phoenixtool 1.98 it can mod the bios and repack the exe file i,e Win1501263.EXE to Win1501263_SLIC.EXE.
I just flashed and upgraded a 1501. Here's the bios. Used andyp's tool also. Tested and verified working. hxxp://uploadmirrors.com/download/W4APUAH8/Win1501263_SLIC.EXE Links valid up until they're not.
Is it possible to re-upload this file to a different site ? This one has a virus --- Avast gets all crazy when I try to download.