Since the 1040 that was prepared when you prepared the amended return form 1040X shows the way your return would have been filed originally had you done it correctly to begin with, just print and mail the form 1040 that is in the file that includes the 1040X. Do not mail the 1040X with it.
ADDITIONAL COMMENTS: This recommendation may confuse the IRS and may not be the best course of action. You should probably prepare your first 1040 that the IRS never received and send it to the IRS. See the comments for alternative ways to prepare the first 1040 again.
