Here is a link to the HK website with the Applcation for and list of requirements ... they, too note that it is 4-6 weeks processing time, which is consistent with my experience and PDLM's experience, though apparently not Smudge's experience.
http://www.immd.gov.hk/ehtml/hkvisas_4_2.htm
It says which forms you have to complete in the first box.