WBTV-TV’s coverage of the Thomas School Bus plant in High Point, North Carolina on their “Carolina Camera” segment from 1981.

Employees are seen affixing a 48 passenger conventional body onto a International S-Series chassis & cowl in this video.

See this earlier post regarding WBT-AM-FM and WBTV-TV:

https://mparij.wordpress.com/2015/11/02/connection-with-the-creator-of-the-arthur-the-aardvark-character-marc-brown/