Looks like telit modem is not coming up on boot. I found something in the SDK sources that it could be broght up by running:
/sbin/telit --hardoff
/sbin/telit --hardon
Then it appears in lsusb, so I set VID:PID to enable admin UI by running
uci set system.module.vid=058B
uci set system.module.pid=0041
uci set system.module.type=3g
However on the next boot the modem disappears again