I can also verify that this modded 1.24 BIOS works for the X61 Tablet. Thanks Yen. Usage of lcreflsh.bat from a USB drive did not work, however. That's never worked with any Lenovo BIOS update I've tried. However, directly executing Lenovo's "command.com" works and starts the interactive flash app.
The Dell OEMIDs are more compressible. At that particular bios the Lenovo IDs don't fit when done the safe 'Lenovo way'.