Re: Adding to a printed Mylar sheet
I doubt a sticky back on a mylar will fly with the city, i don't think that makes it "fixed line". You could use the sticky back and make a mylar original copy from it... then again, fixed line toner mylars don't exist because the developer can flake off, thats a tough one, you might have to scan it and reproduce it on an inkjet mylar.
Re: Adding to a printed Mylar sheet
I recently moved desks and came across a stack of unused sticky-backs that I had not seen in years. I tossed them.