Homelite. The E-Z/Super E-Z and XL-101 series saws used that mount and they were released in the late 1960's.
Really it should be small Homelite. From here on out I will be calling it the K095.
I'm not so sure I agree with you guys on the Homelite useing a K095 mount back then.
The SEZ and such had there own mount with long horizontal adjuster slots in them, not at all like a K095 adjuster holes, and it seems to be Homelites own mount to fit those rectangle adjuster pins they used. Some small Pioneer bars used a mount like that as well.
I know that after those bars went obsolete, the K095 mount was specified by Oregon as the replacement but to say they used a K095 mount way back then may not be completly accurate.