Since it sounds like you need to replace the roof when you have time, glue the rubber down for now and cover the torn areas with dicor roof caulk.
Roofs of that vintage were install with contact cement which was applied to both surfaces and allowed to dry and then rolled into place. Today they use a water based acrylic which will cure without air.
Many hardware stores sell EPDM roofing and adhesives which you can buy to just patch over the torn area. They will be dark grey or black, but since you need to replace it the color doesn't matter. They also sell EPDM for glueing up shower pans under ceramic tile. These will work in a pinch.
If you can't find dicor for rubber roofs then in an emergency I would use standard butyl caulk for gutters from the hardware store. It stays soft and can be removed, but it would be sticky and will stop water.
The other thing you can use in an emergency is the Flexseal. Put some screws with washers to hold the rubber down in place and use the Flexseal to make it water proof. It come in a lot of different colors. Lowes sells it in spray, quart, or gallon.
Joe and Evelyn