Some of this is pretty silly.
V1's aren't magic, might as well say Desert Storm could have been stopped by scuds. Amd an extended insurgency in East Germany after the second world war is highly unlikely with several million Red army troops who control all the food handy.
And Royal Coup? Really? Prince Charles was born in 1948 and Princess Anne in 1950. If they were killed with their mother then Margaret is Queen. If not, then not. Period