These tanks are said to have been made in 1921 and 1922 (or 1923). I have only ever seen these two photographs (both on the Tanks! site):
Tanks! has this to say, "An idea tested from 1921 to 1922 and based on the Medium B. The vehicle was found mechanically unrealiable and the project was dropped as a result. Still stuck on the idea of Male and Female tanks, Tank Number 01 was a Female and Tank Number 02 was a Male. It did provide valuble knowledge for future applications however." Which is taken from Chamberlain and Ellis' Tanks of The World 1915-45.
According to Chamberlain and Ellis, they were not based on the Medium B, merely resembled it. Tank No.1 was armed with 3 ball-mounted Hotchkiss MGs in the turret, and Tank No.2 was armed with a 3pdr gun and had mountings for 3 Hotchkiss MGs, plus a mounting in the roof for an anti-aircraft MG.
David Fletcher in "Mechanised Force" notes that the Vickers No. 1 had a Williams-Janney transmission which notionally gave infinitely variable gear ratios independently to each track. This transmission had been tested unsuccessfully in the Mark VII tank - it was no more successful in the Vickers No.1. Also the tracks were quite primitive and not very robust. The Vickers tank and the gun armed No.2 had a large number of faults - in the end it was considered that it wasn't worth the effort to fix them since the tank was not significantly better than the existing Medium C.