I don’t know jack s**t about measuring this stuff for real, but here’s a back of the envelope guesstimation: My copy does about .9A at the tail, giving about 1.8A to the driver. Assuming 75% efficiency that would give about 1.35A to the emitter. Based on one of Match’s tests that would mean about 500 emitter lumens produced. After reflector and window losses that might leave about 450 lumens.
But for how long you ask? This light, or at least the versionI have from an eBay seller, has a hollow pill and therefore pretty poor heat management without modding it. That means that while it might produce 450 at turn-on, it won’t stay there for very long unless it’s modded for better thermal transfer or you run it in a cold environment.