"Gearbox expansions aren't canon." Black Mesa Research Facility:
bm_c3a1b (bms_c3a1a in Alpha 5) evolution.
Pre-release Black Mesa (pre-2012) is an interesting topic that i wish more people talked about, whether it be images, sounds, or videos, i feel like the topic is under-talked about.
Interesting fact about PS2 HL1, did you know that the PS2 Grenade animation existed during the Dreamcast port days? Yet HL1 PC HD Pack we have, the grenade animation is different from the screenshot, yet they brought back the animation as seen on the screenshot to PS2 port. (Credits to Valve Archive for the image.)