My next attempt, it’s a good 30% thinner, but I want to go further.
I treat it like pastry, I roll it out on a ceramic tile greased with vasoline and then squeeze it with a second to the required thickness - the thinner I go, the less success I have, to the point that this is my thinnest “success”.
Then I cut out the base shape, but leaving three large attachments to hold it still - then I leave it for two hours - not only is it, as you say, far to sticky to do anything with - if you manage to cut any detail into it, it goes through a puffy phase where it will marshmellow any detail you’ve got into it.
After two hours, it’s starting to be ready to carve, but three hours is getting too late. I carve out the outside shape and then curve it over the shoulderpad. After another couple of hours it’s ready for any inside detail - the sword hilt and the divide between the wings and the blades.
After it’s completely set (this time tomorrow on the pictured one above) I’ll trim and file it to clean it up as best I can
(I also plan to paint them in a sympathetic way to help hide the flaws, and leave them stuck only by their own stickiness for easy replacement when I get better!)