I have a right RSX 413 orphan that needs a left. A left in 413, 410 with a length of 170 mm would work fine.
Please let me know condition and price.
If you'd rather buy the A413, which is new with new rings, I'd consider selling as well. The 110 bolt pattern permits you to make decent quality, compact double cranks, i.e. 50/34 for a low price.