switching door locks

[Delorean17@xxxx]

Hello,
I purchased a door complete with everything in it but the guy didnt have 
a key for it. Before I tossed my old door I removed the lock bezel from it. 
my old door has the small little piece that covers the key hole when the key 
is removed, the lock that is currently in the door doesnt have the small 
piece that covers the hole. are all lock units interchangeable? I would 
like to put the lock unit from the old door into the new one.(so I have one 
key for both doors) I dont want to get my door all taken apart and find out 
it wont fit.
Also, is the door key supposed to be cut differently on each side of the 
key? I have taken it to 2 places that make keys and they said they have 
never seen a key cut differently on each side......hmmmmm any info would be 
greatly appreciated.


Thank You
David
#2496-rebrushed yesterday!!