Time Parker needed to engrave Grade 3/DHE?

[Wilmurt]

Reading a few threads recently discussing Parker factory engraving I wonder how long the whole process to engrave a Grade 3 Top Lever or DH grade equivalent would have taken? How'd Parker go about the task, i.e. Did in-house engravers do the scroll work first before going to a contract engraver for dogs/birds or vice versa? Did the guns remain in-house and engraving contractors came in to do the work or done offsite? The Grade 3 hammer I have was ordered in October 1886 and shipped in March 1887, how much of that time was spent engraving?

I can go on and on with questions I have about how Parker put an order through production, but a quick summary from someone who knows the Parker's process would be Just as interesting. Does anybody have such knowledge? Was there any assembly line work where parts were pulled from a parts bin? What were the custom processes particular to each gun? All fascinating questions for me.