Actually the letter after "a" looks like "t" (compare with "t" in "did not see you"), and the whole phrase then is "have been speaking at Lemberg".
The somewhat strange choice of the preposition may be explained that the reference is not to Lemberg (Lvov) as town, but to Lemberg as adjective - refererring to the congress which took place in Lvov those days (and which is described in the local newspaper.
It's still strange nonetheless that there is no punctuation mark before "Stapinski".
The somewhat strange choice of the preposition may be explained that the reference is not to Lemberg (Lvov) as town, but to Lemberg as adjective - refererring to the congress which took place in Lvov those days (and which is described in the local newspaper.
It's still strange nonetheless that there is no punctuation mark before "Stapinski".

