Thanks everyone! If you couldn't tell by the username, I'm the brother/bike owner. I've owned this frame for about 10-12 years, and never paid it much mind. It came with a proper hodgepodge of components, 105 shifters, Ultegra front mech, 105 rear mech, EXAGE brakes, Carbon Ritchey forks, Campagnolo cranks... you get the idea.
The rear stay/seat cluster is a head scratcher. I've had a couple folks tell me it's a pre-production frame from 1985. It is a 1.370 x 24tpi bottom bracket, 1" head tube etc. One thing I'm not 100% on, when I bought the bike it was in this raw carbon scheme. I doubt it would look this good if someone stripped paint off. Not sure if the LOOK livery were decals or under the epoxy, but I doubt the frame would look like it does if a previous owner stripped paint/embedded decals.
Added some more photos for folks, would be cool to find the provenance of this frame!
Thinking about restoring it back to its former glory, or doing a retro inspired bike for cruising around on the weekends. Thanks for everyone's help!