The No.74 is a glass "squash head" AntiTank grenade.
The glass body contained plastic explosives and around the whole there was a sticky compound, covered by two steel halves (during transport, not on photo).
On impact, the glass would break, creating a bigger surface.
Stuck to the side of the tank, it would explode after several seconds.
The fuze was located in the bakelite handle and functioned similar to the Russian UZRG mechanism.
Length: 258mm , Diameter: 127mm. Weight: 1022gram.
Filling: 604gram Nobels No.823
Photo © Dave Sampson.