Darats, I have read your post above.
Sorry for the late response, When I read it, I did not know how to do it.
I use only your parts not others lgeo parts.
I have convert all file in stl dir, to obj format with Poseray.
When I parse LDraw model, for each part I look into directory where files start with lg_
In the lg file I search line start with 'object {'and contains partname I read the obj file associate and apply rotate and translate if the are specified.
Currently I do nothing else.
Binoculars don't have a lg_ file only stl this is why it does not appear.