Correct Rex. The threads for the sludge trap are identical both sides. Actual thread size depends on big or small journal crank type. Cush nut thread is normal righty tighty, the oilpump drive and lock nut are left hand thread, loose off clockwise. These threads are standard across all cranks.
From experience, treat this left hand thread with great care, the crank here is relatively soft, big hammers and frustration are the sure fire way to an expensive disaster. With care the threads can usually be cleaned up piecemeal with a fine file and a good known nut. Pattern replacement nuts are of varying standards, tight impossible threads are well documented on the Forum by those caught out.
Swarfy.