Oliver 88 rowcrop diesel

I have an Oliver 88 diesel rowcrop and am in need of engine parts. The tractor is missing it's serial number tag, but the engine has a casting number of 1K100D with a second number of 190320E cast above it and the date of 8-5-53 cast vertically in front of those two numbers. My parts supplier wants to know if the engine is a DLB, DLC, or DSB? Not only do I not know what those letters mean, but cannot find them anywhere on the block. Can anyone help?

I also need a crankshaft. The casting number on the one I took out is 190111, but then someone ground the 01 out and stamped 12 in it's place so the number might be 191211? Anyone have any idea what this might mean. I have been told that this is an 'early' crankshaft, as the rod pins are 2.25 inches. (I guess the later ones were 2.46 inches) I have been told that this engine was also used in several combines and other tractors but have no idea what make and models they might be. Does anyone have any information that might help me locate a complete engine and/or new crankshaft?

Any help on this would be greatly appreciated.

Chris