After adding a peek tab and waiting a while this AM, I attempted to pull the little 1" sheet of FC from the SRM-HR (surrogate optic) surface.  THe peek tab pulled off, removing a perfect square window behind it where the peek tab had been.  SO, I filled in the hole in the sheet with more FC and reattached the peek tab in another location around the pericmeter of the sheet.  After ~45 mins the peek tab pulled the entire sheet off (with N2 blow).  On to re-alignment of the SRs.