Axis Orbat Tunisia 14 Feb 1943 - G2: http://www.orbat.com/site/history/volume3/issue31-32/AFHQ-AxisTunisia14-02-43.pdf
The 501 battalion was given to von Arnim's 5th Panzer Army, so they did not belong to Rommel. They were part of the rapid buildup of forces in Tunisia to resist the Americans. David