No one in America could have possibly made cases like these without adding their own "corporate" changes to the original design. Only foreigners truly understand the early Harley-Davidson OHV Big Twins.
See for yourself:
http://www.harleymotoren.de/
and.......
http://www.ebay.com/itm/Harley-Davidson-Knucklehead-engine-cases-OEM-Type-Like-original-/120851397906?_trksid=p4340.m185&_trkparms=algo%3DSIC.NPJS%26its%3DI%26itu%3DUA%26otn%3D5%26pmod%3D190613011099%26ps%3D63%26clkid%3D5965382627158981741