(Sometimes) I'm really stupid. 5 minutes after I posted, I've found out if I go to
https://bitbucket.org/Orich/orune I'm able to find the ScriptAPI.cs.
So no worries about that.
More importantly.. I don't know if I was using the method wrong but always when I tried to call a gumps LastGump method it returned a System.OverflowException. I found a workaround what is not nice but it does the job.
I hope to see more good work from you guys, so take your time. I'm happy with what I got till yet.
greetings.