I would contact your Armstrong Representative for your region directly, or go to the Armstrong National office. Armstrong has a recycling program where old tiles are returned to be broken back down into the mineral slop to manufacture new tiles. I went on a tour of their facility which was very impressive. I recommend that should it become an option. Perhaps they can keep an eye out for your vintage tile in the recycling bins?
Either that, or don't sweat the small fissures and don't uplight the ceiling. Other than Architects, who looks up anyway? #ilookup.org
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Philip Mitropoulos AIA
Firm Owner/Architect
Mitropoulos Architects
Douglaston NY
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