Our reproduction Nitrostarch is 4 separate dummy blocks, over wrapped in a paper wrapper. These were based on period engineer photographs as well as several explosive manuals.
Like the originals, the block holes are not prepunched through the wrapper, but each has the correct prescribed cap hole which runs through the entire block. The wrapper can be poked through with an awl, knife, or scissors to insert dummy fuse. Like the photo below, you can also remove the packaging to show the 4 smaller blogs.
From FM 5-25: The 1lb nitrostarch package is a cube comprised of four quarter pound packages. A cap hole extends through the length of the ¼ pound blocks. Its position is indicated on the paraffin treated wrapper of the 1lb package.
A popular explosive during WWI, Nitrostarch was easier to handle then TNT but susceptible to water and moisture. Ironically it was still used in D-Day preparations. It appears in the 1945 explosives and demolitions manual, but is eventually phased out after the war.
This is an INERT dummy for display only.