On the inner side of the brake assembly is a round plate that bolts to side of the differential case. It contains the oil seal. I replaced the seals on my 4 Star. Used National 417344. I also have a note that CR 28699 is an equivalent. Once you pull off the brake assembly the plate is obvious. All brake and seal parts are on the outside of the differential case. #12 on page 57 of parts manual R-2013A is oil seal.
Don't remember if I had to drain some oil from differential to replace seal. Position of oil check plug will tell.
Outer axle seal is in the cap on the outer end of the axle housing. #35 on manual page 53. Seal is #36
I also replaced these seals on my 4 Star. Same seal as uses for brakes, however original was a wider seal so I used 2 seals on each side. I was able to remove/replace the seal through the bearing race.
On my axles the old seal had worn a slight groove ring around the axle which allowed it to leak. On replacement seals I left the new ones in about an eighth of an inch on the end cap to keep new seal rubber out of the groove.
Go to Grandpastractor dot com Tractor Forum scroll down to User Manuals/MM tractors and you will find a parts manual for 4 Star. IT manual MM-201 has info and pictures of brake assembly