On the break up of the Soviet Union copies of Russian military maps of the UK were found (I understand rescued from a burning Latvian barracks). They have been available to buy for a while, but can now be seen on the Old Maps website. The date given is 1990, but actually they are compilations of various data from , I would think , 1960-1980. The Birmingham rail diagrams look particularly like 1960 to me to me. To look at them go to https://www.old-maps.co.uk/maps.html?selection=4 , pinpoint the town you want (not every area is available) and click on it and then click on "Russian map, enlarge" button to the right. If you try to go to home page, click on map and then on "Russian maps" it didn't seem to work for me, but going staright to link above did work
Mike
Mike