Of our two Lamps, but one may shine;
I choose to give my [light/flame] to thine.
Drifting from the original lyric further, but I think it captures the
meaning.
And:
I thought were deathless mirth and sun!
You were spot on about the recording delay; annoying, but fixable in post. I think I've got it right on this version, though I know some of the parts with me singing twice are still broken. So it goes.
hS