Truck bed identification

[Ross.Russell]

Asking for some help. My 2012 Silverado got T Boned but took the full brunt of the accident on the bed. The other driver has farmers insurance and they used a bed they claim is same year or newer. My question is, is the a build date/model/ or serial number stamped into the bed somewhere that I can identify the year it came off?  I have a valid suspicion it came off an older truck cos I’m having horrible rust issues over the wheel arches (yes I know it’s a common fault) but they claim they back the old parts. 
I want an ace up my sleeve when they try and deny the warranty. If it is indeed off an older truck they need to make it right. 
thanks. 

[Sharpz]

The thing is there is more then one year bed for your truck.  That style ran for a few, so not sure why a year is going to make a difference to them.  If the bed they put on was not properly done with primer, paint etc, and it is in a reasonable amount of time this occurred, I am sure they will fix it after trying to give you a run around.