It's hard to tell what this is - a 250Osprey ('cept they didn't make one in 87)? A 271 Osprey? Around this time AS made some "one-of"s. They made a 280/281 Osprey in '88/89 but that thing was a beast. They also made a 270 Osprey.
It could be a 280... Doesn't quite look the profile though. Notice the beam - 9' 7.5"
It's not an XF - here is what one of them look like
