The fourth and last tube made for the War effort by Moorhead Laboratories Inc. was the VT-32. This tube was made to be identical to the Moorhead B except for the shape of the glass bulb. The designation, VT-32, does not fit into either the British or US numbering system so they were probably made after the War had ended and never shipped to England in any great quantity, if at all.
Taken from Joe's article.
Thanks to Joe Gruber for sending the images.
The wide glass tube envelope is mm in diameter and, excluding the B4 base pins, is mm tall.
Reference: Joe Gruber. Type VT-32(M) was first introduced in 1917. See also 1917 adverts.
Updated February 08, 2021.