Checked the link—radiomuseum confirms heaters on pins 2/7, cathode 1/8, plates 3-6. GE sheets match RCA/ARRL standards. If your copy says otherwise, it's a misprint or you're misreading. Pic still looks wrong. Source?
The GE specification sheet disagrees with you. So does the 1972 ARRL handbook, found in this link: https://www.radiomuseum.org/tubes/tube_35w4.html
Discussion
You did not check the link. The link clearly posts diagrams that confirm my pin out. Here is a Pic of the GE specification sheet for further confirmation:
