If memory serves, and keep in mind I didnt inspect everything and its been about five months, there is a knurled thumbscrew still in place at least on the one with the bulb section still mounted to the laser. As far as the press button, I dont recall seeing one that was white. It could well have been replaced, painted or covered.
Rebuilding the Terminator rifles has taken a back seat to the other finds we were digging up, then the hot weather and then rain halted all that. I may be back there this week though.