IIRC Pacman doesn't contain the Namcot logo either... It contains 'Bug-Byte' or something, the licensor

I checked two of my original namco classics on tape. They are DIG DUG and RALLY-X.

RALLY-X cassette cover says:

TM and (c) 1980 Midway Mfg. Co. All rights reserved
(c) 1988 BUG BYTE
A division of Grandslam Entertainments Group
12-18 Paul Street
London EC2A 4JS

DiG DuG cassette cover says:


TM and (c) 1982 Namco
(c) 1988 BUG BYTE
A division of Grandslam Entertainments Group
12-18 Paul Street
London EC2A 4JS

So they are not just (C) BUG - BYTE.

And there is mentioned word NAMCOT on titlescreen in those two and WARP WARP (cassette) too. Titlescreen does not say anything about bug-byte, it´s exactly original NAMCOT title.