I have a 42t / 130 BCD Rotor Q-ring (black). Just bought, ridden 3 times, total 90 miles. Looks "as new".
Would like to trade for 39t ring. (my eyes were bigger than my thighs)

Would also consider trading it for a 34t / 110 BCD ring.

Only interested in trade if yours is in "Very, very good" or better shape.
(fyi: the 42t ring actually retails for $28 more than 39t or 34t rings)