I have a driver side remote from a 72. Driver quality. I don't know if a 70 and 72 would be the same or not. Let me know if you are interested. I can ship or deliver.
If it is really from a 72 Buick A body it will bolt up but they are not the same. 70 models, because of the engraved trishield, were a one year only iitem. The overall shape is the same.
I have gotten the drivers side off a 72 lark, I am still in need of a passenger side mirror. it does not have to be show quailty as this is a daily driver for my 18 year old son.