I have done this PS3 PUP / Dev_Flash File Spoofer v3 Tool (basically is an script that use other tools) long time ago for easily spoof necessary files from a PUP file or your own files of dev_flash. This works on Cygwin and Ubuntu (not CMD windows)
There are 4 tools that makes a different job:
keys.exe - Install PS3 keys
extractor.exe - Extract vsh.self, index.dat and version.txt of PUP file
spoofer.exe - Spoof your flash files [vsh.self and version.txt] (put there in same folder with spoofer.exe)
spoofer_pup.exe - Extract and spoof automatically files of PUP (it must be in same folder with spoofer_pup.exe)
You must choose what version and image version you want to spoof in tools spoofer.exe and spoofer_pup.exe, for example, if i want to spoof to 6.40 i put this on Cygwin console (you can choose any image version):
./spoofer.exe 06.4000 99999
or
./spoofer_pup.exe 06.4000 99999
When it finish you have your spoofed files in Spoofed folder. Version must have same numbers of characters, otherwise it give you error on PS3. If you do something wrong PS3 will boot up Red Screen, if that occurs re-install CFW from Recovery Menu.
File index.dat is really not necessary to extract, it creates a new one with spoofed version.txt (spoofed tools does it auto).
I hope this helps anyone. If you see any error or bug please contact me.
http://www.mediafire.com/?p7484bhsrxgu72n