I've found a third version of the stanza I quoted a while back, by John Frederick Nims of San Juan:
Unready yet to mend
the havoc in this heart--so quick to break it?
Possess and not intend
ever to take it?
Have it by force and forceably forsake it? (1959)
Seeing you've wounded, dear,
this heart of mine, why never stoop to mend it?
Steal and yet leave it here?
By halves a bandit,
neither entirely take it nor unhand it? (1968)
And wounds to show. You'd cleave
clean to the heart, and never think of healing?
Steal it, and when you leave
leave it? What sort of dealing
to steal and never keep, and yet keep stealing? (1979)
I cannot say there is any improvement from version to version. Probably the '68 is the best of the three and the '79 the worst. He retains very little in each successive version, not even the rhymes.
He must have been dissatisfied with the first two, since he tried a third version. I think I would not know what any of these versions is supposed to say without the original to guide me: Why, since you wounded my heart, didn't you heal it? And since you robbed it from me, why did you leave it, and not take the robbery that you robbed? The antitheses are crisp in the original text.
The '68, though is an interesting edition because it has a preface by Robert Graves that cites Lorca!
Barnstone is rather flat in the translation of this same stanza:
Why do you wound my heart
and then refuse to heal it?
And since you took it from me,
why do you leave it now,
abandoning the thing you robbed?