43 2N front seal

The bottom seal is easy to replace by just pullin out the old one and replacing it with a new one.The top one is another story.The best thing to do is to take a punch and pack the old top seal up on both sides as far as you can with out striking the crankshaft and scoring it. Then obtain some cotton roping and pack it into the void that you made with the flat ended punch in the top seal. The TO Ferguson main seals are cotton roping if you cannot find suitable cotton roping elsewhere. Cotton roping is not rope, it is what is first formed in the process of making yarn from cotton fibre. I think that you could use cotton balls if nothing else can be found to use.
This sounds like a poor way to repair a leaking seal I know but I can assure you that it is a proven process and the only alternative is to pull the engine and pull the crankshaft to replace the top seal.
The only crank seal that the TO Fergusons have is cotton roping that is packed into the groove after the crank shaft is installed. I have a TO Ferguson and installed the rear seal just this way over 35 years ago and it is still there.