@ symbols were cut in many different styles, but they weren’t designed as part of a series: they’re separate, special number matrices. Back then, of course, they didn’t have the same use as they did now - if you’re interested, James Mosely’s Typefoundry blog has a great post about them: http://typefoundry.blogspot.co.uk/
Hi Enda; though I can run jobs on the platen, I’m very much not the man to give you a refresher course. If you can make it down to London, I know a few people who could probably help, though they’d be quite busy.
There are many people who know more about ‘true’ type foundries than I do. Your best bet would be to have a look through a copy of ‘A history of the old english letter foundries’ and take it from there, to be honest.
Hi Greg; all matrix making is done at the Type Archive. Off the top of my head, I’m not sure how much matrices are, but I think it’s something like £5.50.