I've been there several times-there is a coastal artillery exhibit there as well. I think the thing on the front of the truck is a tow bar attachment and a block for the radiator. Yes the guns are a Russian captured quad Maxim mount for AA defense. The museum is quite small and there is not much there but its a neat place to visit-especially in the summer time as its closed in the winter! Nice place for a picnic and a stroll. The island is at the mouth of Helsinki harbor and guarded the city. It was originally built by the Swedes and later captured by the Russians. The Finn's used it as a prison and an internment area during the Winter War. Its a very neat place and you get there by ferry from the central Helsinki docks.