That's very interesting, I sort of assumed that this set in the OP was a one-of thing. I watched a set of videos about the whole ARP process - a young lady was in there interviewing and asking questions about the machines and processes. Mainly talking to a guy that looked like the workshop foreman or supervisor. Of course it painted a very rosy picture of ARP, I was impressed; detailing the lengths they go to to achieve the highest and most consistent in tensile strength and durability etc . One worker saying that he previously worked in an aircraft related parts manufacturing facility and that the quality controls in there were not nearly as high as at ARP.