Very occasionally the cast-iron bodies for the Practice version of the X5 (which became the L2) can be seen in collections. The few (3 or 4) that I have seen were each mis-identified as US or German practice grenades. They are very uncommon and the special fuze more so. They were designed in 1958 as part of the programme that sought to bring an 'improved M26' into British service. Eventually, when the L2 HE grenade was adopted, the practice grenade body used the standard empty components of the L2, and was filled with an inert HE substitute.
Apologies for the state of the drawing but it has taken me years to track it down so I expect it is the sole survivor.