There's no requirement to read/speak Polish (I can't) there will be enough folks who can. Once certain terms/words/titles etc are pointed out to you it gets easier.? Again we would not be translating a document's contents only cataloging its relevancy, ie for example military, government, civilian etc.? No one is insisting but if you can make it to London that would be great, it's strictly your choice. For myself I will go but likely tie it with a vacation to Europe or a visit with friends in UK. ?