Dragon, well done on your part to save the grouping as you did . You may want to consider trying to contact the winner of that one document that got away by asking for the sellers help - ? This is a relatively common document that you could find and then offer to swap. Hopefully the seller is agreeable to giving you the name of the winner, and hopefully the winner will understand and agree to part with the document.
The Cross of Valour document is in an interesting format unique to the 16 Lwowski Batalion Strzelców. Of particular interest is how it combines both the Cross of Valour and the Cross of Merit with Swords. Post #188 of this forums KW thread contains variations of award documents, but this one is not pictured. Please consider posting a picture of both sides there:
Cross of Valour (Krzyz Walecznych) - Exile Types