I don't have a neck template drawing but here's a procedure with photos and text for making an accurate neck pocket template or actually routing a neck pocket.
http://www.tdpri.com/telephoto/showgallery.php/cat/576
André, it is possible to start at the bottom of the pickup cavity if you use a 12 inch bit and drill at the smallest angle. However you must stop as soon as bit breaks through. Here's my method and the resulting hole in the control cavity.
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