my guess is that they are the exact same. My WT-2000 and 270se utilized the same key.
When I got my 270 I couldn't resist to open it and have a look inside anyway....was much better than the TV program that night. Since it came without a key I could easliy do the job with a screwdriver by looking how the whole locking thing worked. No sweat at all! You sure can do the same with the 861.