This exhibit is marked as Type 95 and also has the old UK stores code of 10E/95. It was also known as the VR95 and later the CV1095. Commercially it would be the 954 acorn pentode.
The five connections in a ring that fit into the special base that can be seen in the Acorn Antiques article.
The anode end. These is no evidence of this valve having been gettered.
The acorn envelope is 13 mm in diameter and, including the base pins, is 41 mm tall.
References: Data-sheet. Type 95 was first introduced in 1935.