Vintage omega seamaster de ville glass size

Hi to all and thanks. I have an Omega seamaster deville and im looking for help.
If anybody knows the size of plastic glass. I need to order a replacement. I attach some pics from watch

We need the reference number (which is found on the inside of the case) to provide accurate information. It looks like you have a reference 135.020 or 166.020. The diameter you need would then be 31.6mm. But be aware that these SMDV's take a crystal with a notch around the perimeter (I have attached a picture for reference). According to the parts list in the link I have provided below, the part number is px5072. Please know that I do not have the reference of your watch and this is just off the top of my head.

Parts list: https://omegaforums.net/threads/crown-glass-gasket-list.81619/

Another question though - why do you want to change the glass of your watch? It looks in good shape. If it has scratches, these can easily be polished out. Also, if it is an original Omega glass (there should be a tiny logo in the glass in the centre), it will take some value off the watch if you replace it.

Original ones are $75 - they are the PX 5072 ones, so I suggest you buy original: https://auctionstalker.com/search?q=omega 5072&cat=260324

The geometry matters a lot, sometimes just the looks sometimes the armor groove matters a lot

Dome height matters a lot, if it's not high enough it stops the seconds hand, also the armor/ring groove presses onto the dial, so on the models I'm interested in a wrong crystal could mean a damaged dial