Late and lazy Blip. Metric dial calipers. Measurement of the width of that worn out rear bicycle wheel. Original width was 25mm. Much less wear on the front wheel, and now I know to keep checks on it. Think 23mm will be a safe limit.
Plan formulated for fixing the bike. Bits ordered, including a chain and sprockets. Hope to have a working backup soon. That was something I did always try to have, until letting things slip during the car ownership years.