First and foremost, does the machine play back its own recordings OK?
I assume your drum and capstan servos are locked, back-tension looks about right and everything is clean.
I'll let you into the way I did alignment in the field with no test equipment whatsoever except a pre-recorded tape that I trusted was accurate.
You won't see this in any service manual
Instead of concentrating in getting uniform FM carrier off the tape, endeavour to get uniform noise.
Adjust the tracking control for maximum noise, if there is insufficient range, move the control head laterally with the adjustment cone.
Adjust the L & R inclined guides for uniform noise. Don't make the mistake of having both guides too high so you are reading the track above, the tape should be sitting on the ledge of the lower drum.
When you have it right you should be able to adjust the tracking control too and fro and see the picture emerging uniformly from the noise with no banding. If you see narrow bands that walk up and down the screen with the tracking control, you are way out.
Of course, then you'll want to look at the FM envelope on the scope and admire what a good job you did.