Side Mirror for 66 Valiant

Except that your photo of the remote mirror is one for a '67-up model. The '66 and older have a different control and head/base mounting method.
That might well be but it shows the op what the mirror should look like. They made companion mirrors for the right side as well. Same style mirror but non remote unless you have a right hand drive model of car. I think C bodies had those available for the right doors with a long cable so the driver could adjust them from the center of the dash.