I recently received my grandfather's troy bilt horse tiller. It has serial number 525777. I think it's from the early 80's. It has the original 7hp kohler engine, which works great! The rest of the tiller needs some work. It leaks from about every source possible. I have replacement seals, that my grandpa bought, for the wheel shaft, tine shaft, and eccentric shaft. I need new seals for the front transmission. Where's a good place to order this?

It seems I will be doing an overhaul on the transmission. What should I look out for while doing this? I have noticed that the wheel shaft slides about 1/8" left to right, do I need to shim anything here?