this weekend PlayStation 3 hacker naehrwert has updated SCETool to version 0.2.1 which now includes full PS3 SELF file support.
Download: PS3 SCETool v0.2.1 / ZLib1.dll File (Required)
To quote: scetool 0.2.1 - SELFs should be fully supported now.
Finally, from the included ReadMe file:
scetool 0.2.1 (C) 2011-2012 by naehrwert
- zlib is required to use scetool.
- 'sdk_type' was changed to 'revision' in data/keys.