Vintage NOS 29.5mm 1421-1AY Bulova Armored Yellow Watch Crystal
May have minor shelf wear marks from being in a watchmaker’s cabinet for decades.
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I have many Hamilton, Elgin, Bulova, Gruen etc watch crystals, so if I don't have the model listed on eBay, please send me a message with what model you are looking for and I'll let you know if I have it.