Thanks again everyone for your comments.
I have several bottles of Feibing's dye, and the red one just says "Red". My favourite colour for longrifles consists of mostly dark bronw, a splash of yellow, and one of red. Go easy on the red, because it is overwhelming. I lay it on heavily and evenly. It dries quite quickly, and I apply several applications to get the curly real dark. If the wood soaks up too much, clouding the curl and grain, I wipe the stock down with a rag soaked with methal hydrate. This removes some of the surface pigment, but drives the stain deep into the curl.
JP's patch box spring...thanks Bill. It has a tricky bunch of curves, and the length is critical. On some of the pics of his originals, the spring appears to be driven into the end grain on the little step inside the box, but a couple of those appear to me to be replacement springs...the heads are lateral rather than vertical, and the metal thin. The original that I copied is held with a small domed head screw. It's a clever spring. You'd think it would be too stiff because of it's thickness, but the thinned part that presses against the upper wall of the patch box cavity is quite a distance from the knob on the outside of the butt plate, so the mechanical advantage makes it function smoothly, crisply, and firmly, sliding over a considerable amount of hook on the lid latch.
My thanks to all those who have posted and sent pictures of Beck's rifles. They were an immense help in getting the flavour of the rifle.
And Leatherbelly shot it very well. It has one of Rice's gunmaker's barrels with square bottomed rifling. It loads easily with a .490" pure lead ball, Roy's liquid lube, and a .022" thick denim patch. Once a short starter seats the patched ball in the muzzle, thumb and forefinger on the rod will push the ball down to the powder. Our charge is 75 grains FFg GOEX.