Hmm, caffeine_fairy's suggestion of Copydexing the outline I needed to cut from the lining material to ensure it didn't fray would probably have worked better if the material hadn't been quite so porous; it wound up stuck to the newspaper I was working on (and came away with bits of newspaper firmly stuck to it). Luckily I have plenty of that to work with. Spraying it with Spray Mount first seems to work a bit better.
I'm on the next stage of making the bracers now; I've stuck the leatherette to the foam/paper sandwich and am currently sorting out a neat edge by lapping the edges of the leatherette over the rest of it. It is as well that there will be eyelets in some of these edges as I'm having to use clothespegs to hold it all together while the glue dries and it's denting the foam somewhat -- probably not too noticeable.
I realised two things earlier -- one making for more work, one for less work. One is that, looking once again at the page whose armour design I am being inspired by -- I would say "borrowing" but I'm not copying it quite that closely -- I need one more armour piece; the current design doesn't have the breastplate component (look at the first picture on that page; the bit where there's a large lion's head, between the armour straps). That bit probably can at least be rectangular, or close to it, and two of its edges won't be too obvious since they'll be hidden by the shoulder straps (and probably attached to the shoulder straps underside). I briefly experimented with a design for something to go on that plate, first attempting to cut something out and spray it gold, and secondly working out an "incised" pattern -- i.e. drawing heavily on some card so that a visible groove was left and spray-painting the result -- but neither of those have worked too well, so I think I'll probably just have to use a couple of plaques/cards from the rest of the armour. The other realisation, which will make for (slightly) less work, is that the straps which form the armour's "skirt" don't come to a point as I thought they did -- they're straight across horizontal at the bottom. This will at least make the "hem" a lot less effort. (The final cuts into straps will be done with a straight edge and a craft knife, then I will colour the edges with a marker pen where necessary; the leatherette is white on its back and therefore also where it's cut.)
The gold paint I sourced yesterday seems to dry to the same colour as the original lot, which is good, but there's some question as to whether it lifts the glue used by the stickers I'm using on the cards, which is rather less good. Think I'll use the first lot until I run out of it, anyhow.
rotwang raises the question as to how he's supposed to sit down without knackering the cards being used on the back of the "skirt". A very good question, that. "On stools" is the current plan (so that he can drape the armour over the back). I will also be taking a bunch of spare pre-sprayed cards along to the event for running repairs.
The next decision that will have to be made is how to thread the sets of cards together for the tunic. The ones for the skirt's straps are easy 'cause there'll only be two of them on each strap anyhow, but my original thought for the tunic was to put them onto long bits of wire that ran all the way round. Unfortunately someone correctly pointed out that this would make any necessary repairs really tricky, so I may wind up doing it with individual bits of wire running between cards instead. This will be a bunch more complex since the wire's quite a bit smaller than the holes in the cards, so there will have to be knots involved (or possibly I will try twisting a small bead onto the end of each bit, but I reckon that'll make it very hard to glue the whole lot down).