first of all - i updated my bb 05.16.02 3gs to 4.3.3 official then i jailbreaked it using pc using snowbreeze so my iphone got locked (no carrier) then i restored it to 4.3.3 official using itunes then i jailbreaked it using jailbreakme.com and after this i got my iphone jailbreaked and unlocked
so try this and it ((may)) work without needing to update to ipad bb 06.15 for unlocking
1.your 3gs bb 05.16.02 must have 4.3.3 official installed on it
2.then jailbreak it using jailbreakme.com
3.and now see if your 3gs is unlocked or no
note that my 3gs is new bootrom
and i swear that this worked for me
please report your results
so try this and it ((may)) work without needing to update to ipad bb 06.15 for unlocking
1.your 3gs bb 05.16.02 must have 4.3.3 official installed on it
2.then jailbreak it using jailbreakme.com
3.and now see if your 3gs is unlocked or no
note that my 3gs is new bootrom
and i swear that this worked for me
please report your results