Fantastic time at the Vintagers and a Question

[Kensal Rise]

"you can put the lock in uncocked if you push the trigger forward to get the extension that contacts the sear out of the way."

This is probably the hang up. Without photos, it's hard to know "how much" you've disassembled the gun.

BUT... push the triggers down so that their upper blade drops below the sear arm on the lock... as you push the lock assembly into place. Do this on both the left and right lock/triggers. DON'T force anything. If you're still not able to get the locks in, take it to a good double gunsmith. He won't charge much, and will save any damage.