well your trophies are on the Harddrive on your Uni PS3. apart of the game saves or trophy saves i guess. so i guess moving over an new game save with new unlocked trophies wouldn't do anything i guess and just internally update the trophy list. Tho i have no clue and guessing this.
But do you have an Iphone 4. Well i have seen it work between an iphone and an computer but i am sure an ps3 can work despite haven't tried it. But (you have to look up how) you can turn your iphone 4 (which must have wireless internet access) into an wireless router, which other wi fi devices can connect to it. Then you can connect your ps3 to your iphones internet and synx your trophies.
Might give that a try with either yours or someone you know that has an iphone 4
Of Course That's Just My Opinion, I Could Be Wrong