That's a good idea.
I also found this map: http://images.wikia.com/genealogy/images/d/d0/USSR_Republics_Numbered_Alphabetically.png
- this might help with SVG creation.
Including countries of East Bloc would be difficult - the USSR was neatly divided in oblasts, as you can see above, and it could be made straight into a WL map. However, for example Poland was at the time divided in 49 voivodeships - and it's barely bigger than Belarus, which is divided in 6 parts above. We'd have to either cope with it (bad idea) or sacrifice historic accuracy (slightly better, still not good). I'd keep to just the USSR, it's big enough ;).
I might try to convert this map to SVG, but someone else will have to upload it, name the territories, create bonuses and connections etc., since I won't have time for that.
Anybody interested in cooperation? ;)