Dohrn Transfer Co
Rock Island, IL
MC-043421DoT 122431
Acquired by Hall's Motor Transit 1981
Route Map - 1972
Profiled in Mike Terebecki's The Vanishing Trucking Pioneers Book (click image to see Book index)
Acquisitions
Patches of it that are in my project - Facebook Trucking Industry Insignia Patches
Other known patches
If you want your own memoribilia:
Dohrn Transfer items available on eBay
Note that patches sold by "freedomfifty2k" and "bob82ndabn325inf"are likely promo/replica patches, not patches actually used by the company represented.