These are originals from my small collection. Bought these back in the 1960s when I was active in reenacting.

Left to right:

.69
.58 long
.58 short
.54
.577 enfield
.50 (post war for the .50-70 I believe)

You can get an idea of measurements by figuring that the lower swell of the plug fits the bore snugly so is about the diameter shown and then scaling the rest.

The Enfield body is cork with a brass nut on the top that threads onto a machine screw that extends from the bottom.

Most have two sets of slits at 90 degrees to each other although in the photo you only can see the one slit. This allowed the wood to compress slightly for a tight fit in the bore.

You probably already new my comments, but I am never sure. Sorry if I overstated what you needed to know.