iPhone 5S CDMA or GSM, 6,2 or 6,1 ?

Hi,

Well I've identified my iPhone as GSM, being A1457 according to Appple.

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Model number on the back cover:

• A1533 or A1457 or A1530: iPhone 5s (GSM model)
• A1533 or A1453: iPhone 5s (CDMA model)
• A1518 or A1528 or A1530: iPhone 5s (GSM model China)

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Since I have a 8G/month connection, I was going to download the IPSW file to install on my iPhone and since it's a GSM, I would need to install the iPhone6,1_8.3_12F70_Restore.ipsw, according to OSXDaily, but here comes my doubt. When I've upgraded from iOS7 to iOS8, I've downloaded the IPSW from a different site where there was the link to download a 5S IPSW and it wasn't written whether it was a GSM or CDMA, so I did that upgrade, but checking my backup files on another disk, I've noticed that the file for iOS8 was called iPhone6,2_8.0.....

So, basically, have I installed CDMA 6,2 over GSM 6,1 and now I need to update with GSM 6,1?

I'm pretty confused here.