Bruce:
If affordable BSC thread(1.370" x 24tpi) is acceptable, try this link: http://www.loosescrews.com/index.cgi?d=single&c=Bottom%20Bracket&sc= Lockring s&tc=&item_id=LS-1005RC&id=34970511063
If problems with that link, start here http://www.loosescrews.com/ and choose the Bottom Bracket tab, then the lockrings bullet.
Tory WerneWoodstock, Georgia USA