Catacombs Model Gallery
Rocket Gun

This "heavy rocket gun" is seen in The Beta Cloud, The Immunity Syndrome and The Dorcons (continuity guide). It is made of standard ABS tubing; the wooden handle may be from a saw or lathe. The trigger handle is a Paterson pistol grip/cable release, for a stills camera. The same handle is used on the anaesthetic dart gun in Space Warp.

The markings are different to the screen-used models, but the Letraset text is authentic (including the misspelling):
Drain point
Sixteen Nine
Proceedure [sic]
42018 C71
Micro
Extended 54-12-CLN

The Paterson pistol grip (thanks to Simon).