IPHONE 3GS w/out orig.SIM and w/out knowing IOS

[YERUSHALMY]

Dear Friends, help pls.
I've 3GS (new BootRom) IPHONE, but because of I've no original SIM card I don't know IOS ver. & BB.
I want unlock the Phone.
My Q is - if I do upgrade to 4.3.3 with iTunes....ll BB be 06.15.02 and I'll be DO UNDO (return) during the unlocking???
Can I do backup IPSW (4.3.3.) for not activated IPHONE?
Many thanks.

 

[bab2010]

Since you do not know what firmware is on the phone at the moment you have few/less options here. Like you said, upgrade the phone to iOS 4.3.3 using iTunes, once that's done, get the ipsw 4.3.3 from Internet, get snowbreeze jailbreaking tool from Internet, now you ready to jailbreak the phone, using snowbreeze will give you the option to have that 06 iPad baseband on your phone after the jailbreak. But you should know that you will not have the map and location stuff while on the baseband.
You will not be able to downgrade your iOS to any previous version since you've never save any shsh of any previous iOS.

 

[YERUSHALMY]

Many Thanks!
I've another iphone with such parameters, only it was with original SIM card and it was upgraded to 4.3.3 06.15.02 by itunes.
I've successfully jailbreaked and unlocked it with Redsnow and Snowbreez,
and it's GPS works as usual.
...once more, I've understood that I can save SHSH with Tiny Umbrella now before IOS upgrading.