Brass tubes, primer etc

[roller63]

Can anyone help identify these brass tubes, primer and other items in the pictures ? I have little idea as not my field. I think they might be British.
The only things that are marked are the primer : No. 51 V.S.M A 12/15. What looks like a short, tapered .303" case, Mk5 RG 59. The thicker tube with a corroded end is marked : R (broad arrow) L II.
Thanks in advance.

 

[TimG]

From the left, top:-

Tube, Percussion, S.A. Cartridge, Mk5
Tube, Vent, Percussion (or Electric), .5-in (if this is the Mk II, it's a Naval item)
Tube, Vent, Percussion (or Electric), .4-in
(the vents are an educated guess)

The primer:-
No. 5 MkI,

TimG

 

[roller63]

Thanks Tim, That's great. The small item looks like it might be the tip of a small fuze. The two items the same appear to be gaines of some sort, unmarked, threaded internally at the open end.