This is a copy of the official Edimax BR6104KP 2.97 firmware, modified for the SWEEX with
USB mod.

The only difference between a BR-6104KP and a BR-6104K-image is the four first bytes of it.
On a BR-6104K (and LB000021) it's 'WB4K', on the BR-6104KP it's 'WBKP'.
A simple hexeditor is enough to make the router use an image meant for the other model.

Marcel