Contacts Restore

Hello!

So a little background info: I tried using OS 4.5 beta, did not like it, and it ended up �killing� my SIM (soooo sad). I believe that I had been saving all my contacts to my SIM card, so before I got a chance to transfer them to my phone so I could transfer them to my new SIM card, the old SIM was at a point of no return (i.e. couldn�t access my contacts).

Now, the last time I backed up my phone was when I still had 4.5 on it. I had to wipe the OS, and re-installed 4.2. I also do the memory optimization, so technically the version of 4.2 on my computer is my custom OS, set up to how I like it (no wallpapers, certain themes, etc).

My question is this: If I restore my last backup to my phone, which is currently running the �custom� 4.2 OS, what will happen? I feel like because the restore was from a 4.5 OS, some of the issues I had with it might come back, or something like that. I really just want to see if maybe my contacts were backed up, as a last attempt before I finally admit to myself that I have to start all over again 

Can someone reassure me that if I do the restore, nothing from 4.5 which �rub off?� Or should I just let bygones be bygones and be happy that my phone is still alive?

THANKS MUCH!!
E