Reverse flashed Galaxy S3 from Cricket back to Verizon?

[MR OZ]

I made the mistake of not meeting at the Verizon store and bought a Galaxy S3 off Craigslist. It has a clean esn but it won't read the 4G sim card. I found out it was flashed to Cricket so I used Odin to flash it back to the original rom that came with the version of the phone which changed it to Baseband version: I535VRLEC but this still won't work it still has the same problem reading the Verizon Sim.

I guess my question is... if there is a different rom I should flash it too? Or is it that once it has been flashed from Verizon to Cricket it can't flashed back to be used on Verizon again?