@Olethros, thanks for your previous support by PM, I went on searching !
3GS 4.1 bb 5.13.04 Pwned + ultrasn0w, 5 bars and carrier, NO SERVICE, NO DATA.
(Anyone knows and resolved that issue ??)
In /root/Library/Lockdown there is no activation-records folder. It's named escrow-records.
In /mobile/Library/ There is no quick link to Operator Bundle.bundle, neither to Carrier Bundle.bundle.
In Settings>About, network is recognized but Operator not available.
Would you guess it would be save and maybe help to jailbreak again with the redsn0w/PwnageTool combination instead of just PwnageTool ?
Could this resolve the missing bit ?
Or is redsn0w just for special DFU-mode (which PwnageTool provides all the same) ?
Thanks to everybody for constructive comments !