As I know at least in the late 60s full body cyborgs exist (thus a cyborg with just a metasapient brain). I'm wondering though when the first ones existed (prototypes and also mass produced). Is there any info on that?
Around 2065 and 2070
Aparently, their development started around 2065. From 4ed Augmentation (page 148):
Posted By: The Smiling Bandit
Ever since MCT began internally deploying their anthropomorphic Otomo drones back in ’65, folks have commented that things didn’t seem quite right about them.
OTOMO Product Announcement
Limited Distribution: Full Mitsuhama Subsidiaries Only
Clearance: Secure Sensitive Information (SSI) Only
Since the dawn of optional cybernetic implantation, some have pushed their bodies to the limits. As technology advanced, so did those limits. With the advent of cyborg technology, the bar has been raised to a whole new level. Through our exclusive cerebral containment unit (CCU), a metahuman brain can be conveniently implanted in an entirely cybernetic body.
The exact date when mass production started is unclear, but by 2070, you could buy your own cyborg. (page 151):
The preceding fiction introduces Shadowrun players to three different technological breakthroughs that showcase and exploit the cutting edge of augmentation technologies in 2070: biodrones, cyborgs, and cyberzombies.
A cyborg requires access to delta-grade implants. This essential modification raises the entry price of a CCU to 250,000¥.