I’m sure this is not uncommon.
To start sorting it out , I’d ask whether other lots have electric openers . If not, then it’s likely the opener was installed by an owner ( electric openers were uncommon in the 60s).
It’s unlikely thst it’s original as electric openers were uncommon in the 60s, so it was added by an owner.
I don’t think it’s altogether clear,and could be argued a few ways. It’s just how much argument it’s worth.