I did not include the original 1040 or filled out a new one; I just did the 1040x with other documents and IRS accepted. It makes sense to not include the original or fill out a new 1040 since the 1040x is showing only the changes and IRS already accepted and have the original 1040 on file. It is redundant and could lead to more confusion filling out a new 1040 or sending the old one in with the 1040x. This is my experience. I am sure you could do both but it may cause an issue. A lot of confusion on this, I think because you can do both.
