Some years ago I saw a magazine article (or reflector post) containing
some advice on what seemed a very simple means for keeping everything
absolutely straight in the spanwise direction when replacing mylar
seals. For the life of me, I cannot now find that information (which
I recall -- although not confidently -- involved using masking tape as
an index).

Can anyone help me find what I need or, alternatively, weigh in on
what has worked for you?
Thanks.

Mark -- B9