What about Szczombrowski?
Rare as it seems to be, there are appearances of the surname Szczombrowski in contemporary Poland. For example, the data base "MoiKrewni", which is not in any way complete, shows 30 such surnames: some in North-West territories, some in Silesia and Lower Silesia - suggesting immigration from the East.
There is indeed some connection with "Kresy" (Eastern Borderlands) since five such persons (Maria, Emilia, Janina, Józefa, Karol) are listed as being murdered on April 2, 1944 in the village Dydiatyn - gmina (municipality) Kąkolniki - powiat (county, district) Rohatyn.
Source: records compiled on the basis of the book Stanisław Jastrzębski "Ludobójstwo ludności polskiej przez OUN-UPA w województwie stanisławowskim w latach 1939-1946" (The genocide of the Polish population by the OUN-UPA in the province Stanislawow, in the years 1939-1946.
One Szczombrowski is also listed in "Poczet szlachty galicyjskiej i bukowińskiej" (Records of Galician and Bukovina nobility) under the following entry:
[Surname: Szczombrowski; Nickname: Londyk; Coat of arms: Sas; Given name: Szczepan; Nobility recognized by: Halicki Sąd grodzki (Halicz's Magistrate Court); Year: 1782]
Szczombrowski is also listed among families belonging to the coat of arms "Sas", genealogia.okiem.pl/glossary/glossary.php?word=sas
Googling (Szczombrowski nazwisko), where "nazwisko" stands for "surname", forces the selection of Polish records with these two words used. And there are quite a lot such combinations - 12, 3000 of them. They come from Facebook, Pipl profiles, lists of candidates for local administration positions and for membership of Polish parliament, judicial records, university lists, high school lists, real estate ads, sport events, professional lists and ads, etc.
But google does not show geographical names "Szczombrów" or "Szczombrowo", indeed.
Could it be that the "Szczombrowski" surname was created from a cluster of two words "Z Czombrowa", "Z Cząbrowa" (of Czombrów, of Czombrowo, of Cząbrów, etc.), as in "the knight Ziemowit of Czombrów"? In such a case the root of the surname Szczombrowski could be one of the two:
cząber, cząbr, czomber => a thyme
cąber, comber => a sheep's back, lumbar part of ox's meat
Googling "z Czombrowa" brings such interesting entries as "Archives of Karpowicz family from Czombrów", "a book 'Letters from Czombrów' by Maria Karpowiczowa", or "Czombrów - epoka Pana Tadeusza" (Czombrów - The era of Pan Tadeusz), see: multipanorama.pl/main.php?muid=11&mid=678&kid=0&oid=0&cid=85dfb 71c85ac53
The place Czombrów is famous for the fact that there apparently was the last private armed assault in Lithuania. In a footnote to his ninth book of "Pan Tadeusz" Adam Mickiewicz writes: "In about 1817, in Novogródek Province, Citizen U. assaulted the whole Garrison of Nowogródek and took its commanders into captivity."
Actually "Citizen U." was some Ignatius Uzłowski of Czarnków. The armed assault; that is, illegal armed forced extortion of somebody's will, was the result of the judicial process against some Siemiradzki, who won a court case against Uzłowski and was about to take over the Czarnków property.