Hardware reverse engineering - GSM Modem Da Sistemi MT0124

I bought this printed circuit board in an electronics fair. It contains a well documented GSM module by Telit and a handful of components for its powering and RS232 serial level converter (from CMOS level 2.8Volt to RS232 7.5Volt):

Even if the GSM module is well documented and even if the salesman assured me that I'd find the electric schema of circuit board on the Internet, I not found it, and I had to spend 10 hours to make the reverse engineering of pin out. 
This are the pin functions:
1. +Vcc (it works from 6 to 12 Volt)
2. bypass to RJ45 connector
3. Serial DCD (out from pcb)
4. Serial DTR (in)
5. Serial CTS (out)
6. Serial RTS (in)
7. Serial RX (out)
8. Serial TX (in)
9. Reset
10. ON/OFF (pull up, 1 sec to GND to switch on/off the GSM module)
11. bypass to RJ45 connector
12. GND