Russian fiancée and I have searched without luck. History major myself and suddenly wondered what happened to the train? Is it in a museum somewhere? Destroyed, scrapped? One of the small things that are now annoying me, will bug me, until I know.
Which/what do you mean by the train?
Lenin went Zürich-Berlin by the famously-sealed train, and from there to Sassnitz. From there, a ferry to Trelleborg, Sweden. In Sweden he traveled by ordinary trains from Trelleborg to Malmö and another to Stockholm, yet another to Luleå and another to Haparanda, where he crossed the iced-over Torne river on sled, being the border to Finland - which was part of the Russian Empire and would remain so for 8 more months. There is no railroad connection there; Imperial Russia had a different rail gauge from the standard one used by Sweden and Germany, hence the sled trip. It's also here (in Tornio on the Finnish side) that Lenin had to bluff his way through the border checks, posing as a journalist. Then from Kemi in Finland, Lenin took a train to Tampere and then another to Petersburg.
So Lenin did not use a single train, nor cross the Russian border by train. He did however cross into Russia proper by train.