Shore power plug to cord separated

We had the IDENTICAL cord with the same problem earlier this year. I replaced the plug with one from a local RV store. Later, curious I dissected the old plug, the rubber was solidly injected around the wiring to form the plug, no open areas at all between the wiring and blades of the plug. Wishing after that I had done what CA Traveller suggested, just tape up the broken casing, there was no sign of any open wiring.

Beverley and Ken