Thanks Saket. Will wait for some more advise from 1200 owners.
Well, the cueing lever is fine. Does what it exactly needs to do. The tonearm ascends and descends fully and correctly using the lever. I fixed the height adjustment dial and also set it to 25mm which is recommended for the 1200 (while playing it is parallel).
I am going to make a very simple box type dust cover this time made of 3mm acrylic.
I have edited my post; hence, please read again. The thought struck me when I saw the picture of the tonearm assembly sent by you. Hope, this was what you were looking for.
Regards,
Saket