the shell is in a decent condition. Shouldnt the HE filler blow up when penetrating the armor? And do you know if it is sabot or normal APCR round? And the distant maybe?:P
It's can't be a Sabot round, as they are just needle's.
The only British rounds with the HE filling were ABCBC-HE, and that is missing the Ballistic cap, and the Armour piecing cap, no sign of there ever being one, so it's assume it's a solid shot.
SVDS ( super velocity discarding sabot) was the old name of the current APDS (sabot) and yes the N0 5 is the 17pdr APC actually showed on the op picture, the APCBC shell is the N0 7 on my pic.