I have decided to take advantage of some additional functionality from Blogger, and start adding some permanent pages with reference material. They can be accessed from the navigation bar above the posts on the home page.
So far I have only posted one page, and it is a very rough draft at this point. The intention is to have three lists of metal manufacturers, sorted by size. The list will include both present and past manufacturers, and give an overview of the ranges offered. The page will replace the link list on the sidebar, which will help make the blog easier to use.
Eventually, there should also be other pages showing which current manufacturers cover each historical period.
I will not bother doing the same work for the plastic ranges, as they are already fully covered by PSR.
As mentioned, the document is still an early draft, and will be updated over the next few weeks to make it more user friendly.