The architectural drawings are available and a perfect replica of the sign should be made. Sooner or later, everything at the site will need to be replaced because the camp was meant to be temporary.
Before the Nazi Germans started to kill Jews at Auschwitz, they first murdered Red Army prisoners, of many ethnicities, i.e. Russians, Ukrainians, Belarusans, Kazakhs, etc.
The most murders took place between June 1941 and January 1942, when the Nazi Germans murdered an estimated 2.8 million Soviet POWs primarily through starvation, exposure, and summary execution, in what has been called, along with the Rwandan Genocide, an instance of "the most concentrated mass killing in human history ...."
This topic has been raised at the John Demjanjuk trial, because he was a Red Army prisoner taken prisoner, and therefore a victim much like the prisoners at Sobibor.
Interestingly, as far as I know, no German Nazis have been tried for murdering millions of Red Army soldier-prisoners --nor has Putin or any of the other Kremlin characters ever demanded that the Nazi German criminal be brought to justice.