RE: the "submit form" link on the PDF did not work:
Depending on your software versions, sometimes built-in functions in Adobe PDF may or may not work. (I get these errors all the time with my basic Adobe Reader version for many PDF documents from all over the web). But there is a work-around, and you do not need to use the "submit form" button:
Save the PDF blank order form onto your hard drive with a new file name. Then fill it in with your order details on your computer, and save it again.
Then make an email to Higginson's and attach the PDF as an attachment.
RE the out-of-stock issue when you saw it in-stock on the online catalogue: Yes this is an old-fashioned catalogue system that has to be manually updated by someone in the shop, and not a real-time instant inventory system. I like to put it in perspective that it is only old-fashioned by a few years, i.e. most of my life was entirely the old fashioned inventory system for everything, everywhere, so while I notice it, I am not stressed-out by it. We all get used to online real-time inventory systems very quickly, because it is really impressive and convenient, but somehow we survived up to just a few years ago without these amazing systems.
Despite the "old-fashioned" system, Higginson's is my preferred shop for primers and the Hodgdon-owned powders. Their shipping costs are the lowest in my experience. Usually there is not this global shortage which generates the crushing demand, and the busy message when phone calling. (I get my Vihtavuori powders from other CGN sponsor vendors who specialize in those powders).