What I call "conditional", a term I learned studying Spanish and French, is, as far as I can tell, the same thing as older past subjunctive in a main clause. It is often, but not always, accompanied by an "if" clause in past subjunctive.
Part of the ambiguity I mentioned is that past subjunctive and past indicative look alike for most verbs, so that we have to use various devices to make "conditional" and the subordinated past subjunctive more obvious. For example, dropping "if" and moving "should", "were", or "had" forward to replace the "if" is a sure sign that past subjunctive is meant.
But in a main clause, the most we can do if we want to "translate" to "modern" is to use the ambiguous "would"/"should"/"might"/etc. and hope the rest of the context helps. Unfortunately, we can't say "would will" or "should will" because modal "will" lacks an infinitive. So we have to look for another verb, like "hope".
Unfortunately, "hope" no longer allows a "that" clause in subjunctive and we have to add another ambiguous past tense modal.
So "I would you were" = "I would hope you would/might be" / "I should hope you would/might be", approximately. Somehow, we just tolerate the ambiguity.