I'm afraid I'm not going to be able to help you to sign up as a packager
I'm certain I can't get you into the packagers forum, though I'm a "moderator" of sorts over there, I don't have access to the magic wand to modify your account. I'm also unsure what my "repo" rights are.
I'm sure glad to see your eagerness and willingness to help though
The more people we have on board makes for a more complete repo. And of course you may have ideas for apps to package that we haven't even thought of.
I must warn you that our packaging standards have tightened up considerably since the packaging "how to" was written. Just recently we've cracked down even harder, and a new slackbuild template created. A new "how to" is being written as time allows. But if you are able to compile and install for yourself, you already gotten past the hardest part.
JohnB316 will get back to you as soon as he's able, he's a good guy.
BTW thomh38.... to get 3d support with gnubg, you need to have gtkglext installed. Otherwise it will quietly build with 2d support no matter what options you pass to ./configure.