The main Tektronix site in Vancouver was the Jack Murdock Park with building C1. There were two other sites also in Vancouver.
This February 24, 1978 TekWeek article describes the move of Plastics to Vancouver, Washington. They occupied building 08, also known as V1, located at 3000 Lewis & Clark Hwy (14).
This 1978 photograph shows the aerial view of building 08 between the oval track and the Lewis & Clark highway at at 45.620262 -122.639707.
In 1979 the occupants of building 08 were plastics, cable & wire, transformers, and support staff including:
Stock and Kit Preparation
Plastics shipping prepack
Methods analysts-mech comp
Tektronix had also leased buildings Y1 and Y2 in Clark County in the Yearout Industrial Park. This location was 12 miles east of Vancouver. The Service Instruments Division (SID) occupied these facilities in preparation of later moving to C1. We do not know how long they occupied these buildings.
This March 7, 1980 TekWeek article features SID. Click on the image to view the PDF.
This Google Maps street view is looking NW from 45.6906 -122.5502. It has the same "3" on the building as in the SID article photo.