I have recently purchased a walking foot for a 1972 Kenmore, while the foot is not marked or have the guide, what I did find is the measurement from the edge of the foot to the needle is scant 1/4 inch. Could your walking foot have this same feature?
For a short time I had the Vintage Bernina 830 record and purchased the walking foot ensemble which included 3 different feet, one being the 1/4 in foot. Is that an option?