Hi Bob attached is the tech sheet for the ronda 515.. If you are replacing the movement they come with stem attached therefore get a new crown at the same time the stem tap size will be on the sheet.
Ronda 515 - Technical Communication.pdf
Hi Glasso welcome to the forum I have attached the tech sheets for the miyota OS11 for your intrest, Follow jdm's advise and pick out what remains of the glass carefully look and see if it has a gasket sealing the glass if so be careful removing it. Once measured and you have the dimentions Cousins.uk watch parts will be able to supply or on ebay look for a seller "watchfan" he seems to have a comprehensive list.
Miyota 0S11 - Specification.pdf
Miyota 0S11 - Parts List.pdf