A (slightly) delayed update:

• approx. 30 sheets of a 1:50,000 (GSGS 4529 Med 4) dated 1945 (Austria), a re-scaled copy of an Austrian and / or German 1:75,000 map. The series was published by the  'Survey Directorate AFHQ' (Allied Force Headquarters). As there's no modern index sheet for this series in mapster, you can use one from 1945 that's available underneath the list of sheets. The series is marked on the index sheet, in the bottom-right corner, in GREEN. For those interested in AFHQ history and structure, here's a pdf file.
• a few British and US 1M map series covering Europe and Asia (AMS 1301 / AMS 5301, 5302 / GSGS 2555 / GSGS 4646), dated 1940 - 1965. There have been quite a few of series in this scale and they might be continued until today and we have no time to figure out details and nuances, they have 'provisionally' ended in one bag (list).
• right in the same 'bag', about 20 sheets of a British small-scale (2.5M) map series  GSGS 4340 / HIND 1080) which covers Asia, though the sheets started from... the Black Sea. Some scans are doubles, but here and there, different publishing dates are available.
• Himalaya, 3 (out of 4?) sheets, ‘Tibet and Adjacent Countries’, 1:2,5M.
• ...and one (probably out of 2) sheets of ‘Highlands of Tibet and Surrounding Regions’. Interestingly, the map shows a dense network of railways, most of which no longer exist.

• a few small-scale Soviet and Russian maps
  (Please note, the map of Soviet railway network is a very large file, approx. 120 Mb)

From the collection of Leibniz-Institut für Länderkunde

• approx. 40 sheets of the ‘Topographische Karte’ (Messtischblatt), 1:25 000, the ‘western’ part, i.e. west of the Oder river - these are the sheets we overlooked during previous update,
• approx. 1000 sheets of the ‘Topographische Karte’ (Messtischblatt, 1:25 000, the ‘eastern’ part, i.e. east of the Oder river , mainly Western Poland. Majority of those sheets have already been available, but some of the new ones have different publishing dates.

All Leibniz-Institut fuer Laenderkunde maps, though scanned really well, are available only at 300 dpi.

From the collection of the University of Berkeley Library, unfortunately also at 300 dpi only:

• approx. 700 sheets of a German „Russland” map, 1:50,000 dated 1942 - 1944/45; the map covers the arc of Eastern Europe, from the Baltic States, Belarus, parts of Russia, to the Ukrainian border against Moldova /Transnistria along the Dnieper (Dnipro) river and, in south-east, probably extended past Crimea and possibly covered the east coastline of the Black Sea
• approx. 20 double (x2) sheets of the same map, mainly from the central area, i.e. current Belarus. Unfortunately there's no index sheet in mapster available, so the sheets were put on a list.
• approx. 50 sheets of the same 1:50,000 map, but in a joint edition, i.e. x 4 single sheets.
  

As to the map type itself: German 1:50,000, under a code-names of Eol 50 (Ostland) and Esu 50 (Sowjetunion) based on a compilation of map sources: captured Polish maps by WIG, likewise Lithuanian, Latvian and Estonian maps, but primarily, based on massive cache of Soviet 1:50,000 and 1:100,000 maps, additionally updated from German air photos from 1942-1944 and field reports. We don't know the extent of this map type, so when mapster index was drawn, the range was rather... excessive, stretching to Berlin in the west. No cler, original German index sheets are available (yet), we added what was at hand below the index sheets of single and quadruple sheets. Given the area covered by this map type, and number of war-time editions, estimated number of sheets could have easily run into a few thousands, or more. However, we do not expect to add any further sheets either this year - or the next either.
It needs to be acknowledged, that using this map type in mapster is difficult; firstly, because mapster database of place names does not extend to the east. Secondly, mapster index 'background maps' do not extend east of Poland either, so it's hard to identify individual map sheets against large terrain features, such as cities, rivers or large lakes. Thirdly, you can't see sheet names on the mapster Russland 1:50,000 map series. We will try to improve it somewhat by adding sheet names to the index, but please bear in mind it's over 700 German, Russian / Lithuanian / Ukrainian place-names. They need to be located, checked and entered into database manually, which is a very time-consuming process - we'll start from the larger towns / sheet titles.