Alex, you're so close I'm going to have to give it to you. This is actually a Sisu xa180, the first of the "xa" series. Many xa180 were upgraded to xa185's, only difference being the engine and transmission. It's not an xa200 because the 200 series had periscopes, night vision, and an even larger engine and was no longer amphibious. These vehicles also are now made by PATRIA. Unfortunately, your answer came after three clues so there is no "grand prize" however we offer the consolation prize of bestowing upon you membership in the Cliff Clavin Master of Esoterica club! Congratulations! (fanfare!)
Stay tuned for the next episode of, "Name that Vehicle!"