I have a load of old topographic maps for whole of Romania in Ozi format
"found" them on the web a couple years ago
two problems
1) the are old
2) they cant easily be merged into a single huge map, because they have borders round the individual maps sheets (scanned from paper copies i assume) so you would have to work with separate map tiles or use photoshop to crop each one to remove the border, then adjust the georef points in Ozi.
i did this for the old morocco maps i have and it took ages, and romania has 100's more tiles!
but ozi does load adjacent map tiles as you drive along, it just makes the planning part harder