Brewsky, I spent a good hour today and still the same. My battery tray measured the same as yours 3.5" so that must be right but the cover only measures 3" so that's where the difference is and why it won't fit up to the framework.
The measurements are a little deceiving from the camera angle......the tray itself is only 3", the additional slot dimensions are 3 1/4" and 3 1/2" out.
After looking more closely at mine, it too sits away from the frame a little bit, maybe 1/4", at the bottom, so maybe just the angle of the bottom tab on the cover makes the difference.
66 dream, 78 cb750k, 02fz1, 09 wing
Well thanks for all your input but there seems little I can do with altering the battery tray so I suppose I'll have to live with it unless I find an early battery cover that I understand to be a different shape. Thanks again.
You need a 'late' style (post '63) cover to fit that bike. Here is my 1962 bike which uses the 'long' narrow batter that your cover fits.
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160
'66 Matchless 350 '67 CL77
'67 S90 '77 CB400F