ok, it tooks some days to implement these.
Changed /usr/gnu/bin/echo to echo, all other /usr/gnu utils to their Solaris10 blastwave implementations, fixed libraries (pcre, libtool) for different components of ThirdParties builds, changed sudo and sudoers and so on. Total 9 local commits after each fix. Perl Modules are building automatically but SpamAssassin, for it - I'm editing Makefile after it is created.
Packages now can be installed. Upgrade fails. Some of the things I missed till now - whoami is called although it should not. At package installation time there are a lot of chown attempts without proper parameters. /opt/csw/etc/sudoers has 0000 mode but should have 0440.
Although it is, by my opinion, very close to be working, but I can't estimate how much work still is required for the packages to get them working.
If there are patches or updated instructions for 5.0.12 building for solaris-10. - I would be very glad for sharing them with me.