The perverse method is recompilation of one map again and again. As Russian and Uzbekistan JSC of Navicom do!
If you use original polish text source and then only add new data or edit old it will the beautiful way always. A transparent map give only new details but do not correct the old. ddabcd277, work you for Navicom? It is familiar stile of map drawing from this company. In some place we have on Russian map a three road (one from 19 century, another from 20 century, and last from 21 century). All are routable. It is very interesting to know what centuries-old trees grown on historic trade route.
No doubt small errors will took place but it is not such critical in case of topo map. Moreover this errors give more precision position sometimes due to random compensations.