correct sling for a holland e holland n. 4 sniper rifle

[Warren]

A most interesting chest!!!!!
It has many attributes of the No.7 .22 chest.
It is the first No.15 chest I have seen with the brush and jag holder plus nuts and bolts attaching the handles which are slings as were the no.7 chests.
Again, a most interesting chest...........

Added after taking a second look:
The jams are upside down cradling the rifle for display. However, if you look closely at picture #3 in the lower right hand corner you will see the cut out for the cleaning rod for the No.7 rifle chest on the jam. I suspect the chest is a No.7 chest with the wooden semi circles around the hasp lock removed. It is not possible to determine the depth of the chest from the pictures but everything says no.7 chest. Also, no scope can lock, nor rails for the scope can and cleaning kit inside on the bottom.
99- 44/100% sure the chest is a No.7 chest.....