I think most of us believe he typed them himself.
If Burkett typed the papers himself how did SeeBS know he had them & why did he make them spend all summer begging him to give them up? Why else would he have typed them other than to pass them to SeeBC or the Kerry campaign?
Burkett did not manufacture these.
The Dems and Kerry campaign knew about them before Burkett had them.
I suspect They dumped them on Burkett, covered their tracks, and and tipped CBS off where to get them