AutoCAD Inventor :: Models Of Standard Bottle Threads?

I'm working on some bottle concepts and I have a need to model standard plastic bottle threads. These threads are designated by a diameter in mm and how many threads are on the bottle. Example: 33-400  The 33 is the diameter and 400 refers to a single turn of the cap. Manufacturers like Aptar make bottle tops of various types to fit this spec. I happen to be looking at dispensing lids (think Heinz Ketchup bottle). While I've found specs for Major diameter, Minor diameter and TPI, I have found precious little that describes the thread shape itself. I've tried to reverse engineer a sample thread from... you guessed it.. a Heinz Ketchup bottle. I feel that my venier caliper and micrometer are not doing this effort justice. 

Looking for DWG file or Inventor model of the thread profile? 

I'm using the coil command to create the thread on the bottle neck. It works okay. An issue arises with the thread termination. The threads on the bottle itself "chamfer" into the bottle neck. While I don't think I can do this with the coil command itself, how to create the "lead-in" for the plastic thread.