Originally Posted by Millertyme
it sounds to me like you are putting the door in backwards if the threshold is on the inside like that. are the hinges going to be on the outside of the house?
OP said an out-swing door, hinges are on the outside and the threshold will be seen on the inside.
If you can not exchange it, I would remove the supplied threefold and find the closest (in size0 oak threshold to use as a replacement. You might have to do some cudtom milling on the new threshhold. Getting it weather tight will be a the issue, which can be difficult on an outs wing door in any case. If the door is protected from the weather you will have a better chance.