Why would that big Mullane shell have a wood fuse plug? Couldn't the hole be threaded? Since it was obviously a photographer's prop, taken from somewhere else, would they not try to deactivate it prior to placement by the big gun. I believe it most likely had a percussion fuse. A wood fuse plug with a paper time fuse was not wanted in close combat with ships or shore. If it actually did have a wood fuse plug, then I suspect it was set up for a Girardey's percussion fuse. I assume this was a CS Navy shell. They put lots of percussion fuses in their ammo. By mid-1863, the Navy was ordering lots of Girardey's fuses from Augusta where there was a machine for mass-production of those excellent percussion fuses.
The pages below contain some interesting info for all Mullane lovers. The first page, an order from January 1864, directed the Savannah batteries to turn in all Mullanes with the "Tennessee cup" and replace them with "projectiles with the Parrott sabot." I wonder do they refer to the familiar wrought iron cast-in cup or the late-war cast-on copper ring sabot? I have a contemporary letter calling for the replacement of all copper Tennessee sabots with iron which testing proved worked just as well.
The second page identifies John Mullane, a civilian ordnance agent working out of the Montgomery Arsenal. In 1864, he was transferred to Danville, VA, to produce wrought iron 3 inch Rifles like the popular Federal Ordnance Gun. Tredegar's records confirm the production of at least one such "Mullane Gun."
The 3rd and 4th pages discuss the field testing of the Mullane Gun in the western theater. The results were unfavorable which was blamed on the projectile's (a 3 inch Read-Parrott, I think) sabot failing to take the rifling grooves. By the end of the war, Mullane was ready for the large-scale production of wrought iron 3 inch Rifles. I wonder if any were made?
Woodenhead