I know how Moscow and St. Petersburg sound in Russian (some think like ?masKVA? and ?sank pietierBURK?). And I think that correct Lojban names are {la masKVA} and {la sank pietierBURK}, respectively.
There is an official transliteration system for transforming names written in Cyrillic into Latin symbols. According to this system Moscow is Moskva. However, the second ?o? sounds not like Lojban?s ?o? (since in Russian there is no one to one correspondence between letters and sounds). The ?o? in Moskva sound similar with Lojban?s ?a? (in English ?but?). Strictly speaking it sounds a little bit different, but anyway it is closer to ?a? rather to Lojban?s schwa ?y? (like in English America).
Moreover, Russian ?e? is definitely not Lojban?s ?e?. It is why I have replaced ?e? by ?ie? in St. Petersburg.