The SEARCH facility for this Forum is located at the top right. Learn to use it as there are literally thousands of tips and hints on most models of Commodore. As for Workshop Manuals, there has been a lot of discussion by members/users. Here are some links, have a read: http://forums.justcommodores.com.au...u/forum.php&ss=3298j781134j18&sa.x=18&sa.y=13
I think you will find it difficult to get anything specific to LPG models, as any work on LPG components has to be done by licensed gas mechanics/installers.