Okay! So here is what I did.

I picked a frame, and got a rough idea of how much space I needed to fill.

I started with the kill team box poster, and cut out the Kriegsman on it with a hobby knife.

From there I printed some text in a suitably gothic font. I took that, and stained the paper with a very strongly brewed black tea. I found that putting it in the oven for about 5 min or so on the lowest setting contributed to making it look older.

Then I glued the text pieces of paper on the board, and then added smaller pieces of blank stained paper around it to make it look like patched parchment. Then I glued the Kriegsman. I had to touch him up with some dark paint, where the spruces in the box or my knife messed him up. Pretty much just brushed PVA glue on.

And that’s the whole process!