Yes, the company is still in business and manufacturing 300Bs:
Western Electric 300Bs
The company has changed hands over the years, and the manufacturing facility was even relocated at some point (in the late '90s, I believe). Most regard the NOS tubes as being notably superior to the current production 300Bs. Nonetheless, the reissue tubes are very good and are still regarded by many as being the best available 300Bs in current production.
However, some of us (myself included) have found that the Sophia Electric Princess Carbon Plate 300Bs outperform the WECo reissues in head-to-head comparisons in our own audio systems.
Western Electric 300Bs
The company has changed hands over the years, and the manufacturing facility was even relocated at some point (in the late '90s, I believe). Most regard the NOS tubes as being notably superior to the current production 300Bs. Nonetheless, the reissue tubes are very good and are still regarded by many as being the best available 300Bs in current production.
However, some of us (myself included) have found that the Sophia Electric Princess Carbon Plate 300Bs outperform the WECo reissues in head-to-head comparisons in our own audio systems.