I fixed the water pump leak on my 1930 L and it was a real challenge. On my tractor there is no seal cartridge. The shoulder on the impeller contacts a mating bronze surface on the housing bushing to create the seal.
A radial bronze sleeve bearing at the rear supports the impeller and a double sealed ball bearing at the front that supports the belt tension radial load.
There is a vent hole in the bottom of the housing that allows any leakage to drain out and not get into the area of the ball bearing. If you are getting leakage out the front of the housing, is your vent hole corroded shut?
The OD of the ball bearing needs to remain a slip fit in the housing and not become rusted and stuck. A spring pushes forward on the OD of the ball bearing. This force keeps the seal surfaces under a load equal to the spring force. The ratating fan also pulls froward and helps keep the seal surfaces in contact.
My C water pump seal is like the L water pump seal. My DC pump is different than the C and probably the LA is different than the L--both later tractors having a cartridge seal. A DC water pump will not work on my C--too long. An LA water pump may not work on an L. I am not completely sure about that. Maybe someone else knows about the L and LA pump interchangeability.
TCM in Iowa rebuilt my pump for a very reasonable price. Can provide you more details if you are interested.
SO HOW DID I GET THE WATER PUMP REMOVED WITHOUT BREAKING THE HOUSING? I rounded up six small screw drivers and sharpened them to where the edge was thinner than the water pump gasket. With the radiator and the two elbows removed from the block, pound these six "wedges" in uniformly at the gasket. This is the same principle as splitting wood with steel wedges.
First, pound each wedge just enought that it will stick in place. DO NOT wedge againist any of the three ears because the ears are weak. place two wedges between each set of ears. Drive the six wedges in a little at a time--uniformly.
On my tractor, this method extracted the pump from the block. Once the pump starts to move and a small gap appears, start using penetrating oil down the gap and letting it soak for hours maybe a day.
The wedges created minor scuffs on the block face and the pump mounting face but a little fileing and gasket sealer took care to that.
Let me know if you decide to proceed. There is more that I can share with you but this is getting long.