C. F. W. Walther, first president of The Lutheran Chuch--Missouri Synod, once presented and explained a series of theses entitled "The Evangelical Lutheran Church [is] the True Visible Church of God on Earth." Contrary to his title, he did not point to any actual communion. Rather, he pointed to the doctrine of the Evangelical-Lutheran Church as it is expressed in the 1580 Book of Concord.
A contemporary antagonist, J K Wilhelm Löhe made the same move in his "Three Books Concerning the Church." Like Walther, he doesn't identify a particular Lutheran communion as the true visible church, but rather a set of documents which, when confessed and practiced, reveal where the true visible church may be found.
I've always found this move not only dissatisfying, but also slightly disingenuous. Not that these pious men were purposefully disingenous. Swimming in the morass of what 19th century Lutheranism had become, they were genuinely trying to call the Lutheran Church back to its roots and urging it to live up to its own confessional standard. However, in their heralding, I find it significant that they could not or would not say, "Here, in the inter-communion of these churches--here is where this true visible church is."
To be sure, Walther honestly attempted to make the LCMS that communion which was in this "true visible church." However, I again find it significant that he refused to say that his own communion--together with whatever communions the LCMS was in communion with--constituted that "true visible church."
In the end, then, what he and Löhe (and others) argued for was what I would call "invisible visibility." In other words, the true church is manifest--but only in a way that no one can see it. To my way of thinking, this is rather a dis-incarnate way of identifying the ecclesial Body of Christ.