Well you can try using the Sprint stock exe, so that it puts the default radio back, then unlock again using Cokeman's 0.40 unlocker, then flash the dumped Verizon ROM back on. But that sounds risky
I don't think its wise to flash another carriers exe ROM on the phone. Sorry I just had to make sure I made that clear, in case something goes wrong, lol.
This is the warning from ImCokeMaN
"WARNING: These carrier shipped EXE roms will include a stock bootloader and "relock" the phone if using the o.40.CoKe SPL. I suggest nobody should use shipped carrier exe roms from a different carrier with the 0.40 unlocker as if it gets interrupted and your carrier doesn't have a shipped exe you might not be able to flash ANY rom."
So I guess you can try to flash the Sprint EXE, make sure you don't let the customizations run by resetting the phone, then unlock using 0.40 unlocker and flash the Verizon stock ROM.
You can also go by these instructions :
http://forum.ppcgeeks.com/showthread.php?t=24906