Specifically, Gryph is in
Barony of Oldenfield.
Gryph, for doing a standalone gamby, you want a sewing machine. Just think of cloth as just another material; you don't need to be in a priesthood of sewing mavens and couturers to make creditable use of a sewing machine. The mavens are very helpful, though, in pinning and test fitting and style advice. A gamby can be made in the menswear styles of a given nation and century, so it can even sport some pizazz. Late fourteenth century fabric armor looks a certain way; early, middle, and late fifteenth, others, though they often share a wasp waist and puffed chest. But a basic yet good looking fourteenth century bascinet is easier to come by than a lot of fifteenth century hats -- and can look every bit as German as you might like! Though fourteenth century armor is also called "international" by some because it was mostly variations upon a theme, all over most of Europe -- England, France, Burgundy, the Germanies/Holy Roman Empire, Italy.
But also, what do you have for tools now, including tools/shop you can reasonably gain access to? Cutting and whittling at plastic doesn't take much, and leather takes little more, to start out, anyway. Butted mail takes few tools at all, riveted mail wants a heat source but otherwise only a couple more tools than butted. Working steel takes a big hammer, a little hammer, a medium hammer; files; clamps in profusion, Vise-Grips at least; a saber saw and a fistful of blades; electric drill, bits, wire brush head, extension cord. A work bench with a bench vise makes a thousand things much easier. You can use an anvil if you have one, but you can do plenty fine without. If you have to you can dish sheet metal into a bare spot in the dirt.
Re concussions: speaking of your own personal head, what sort of helmet or helm do you think is really neat-o?