Thanks a lot.
לעוו is also a transliteration for "Loew". I guess it's similar to German where the last consonant is written as 'w' /v/ but pronounced as /b/ and sometimes also written as 'b': "Loeb" (or with a different spelling: "Leib").Russian Jewish surname Lev (Лев) was usually put as לעוו or ליעוו, while the given name Leyb was spelled as you wrote: לייב
Wikipedia said:Löw (or Loew) is a surname of German and Yiddish origin. Another romanization of the Yiddisch name לייב is Leib.