TO-30 refurb

Thanks in advance, sorry for the rambling
Mike

Check out your distributor to make sure the bushing/shaft aren't worn. make sure all the primary ignition system wiring is in good shape and the connections are clean and tight. Your spark plug wires should have copper conductors and the insulation should not be cracked or frayed. The distributor cap terminals and sockets should be free corrosion and the cap should not have any cracks.

If the trans/hydraulic oil is dirty or creamy colored (due to water) change i. There is a excellent description on how to do this by Jeff(OH) in the archives so do a search and find it. It takes 6 gallons of GL-1 type oil that is available at NAPA and elsewhere. Your oil seal leak may be a result of water in the trans/hydraulic system causing the fluid level to be too high
Clean the airfilter element out. Ytey are usually crudded up. Clean the oil cup and add clean oil.
Change out the engine oil and add a good detergent motor oil and replace the filter. A spin on filter adapter and filter is available to replace the original but there is no problem finding the OEM filters. Flush and drain the cooling system and fill with 50/50 ethylene glycol anti freeze.(The radiators in these old beasts are often in sorry shape due to the use of hard water for the coolant, leaving lime deposits in the rad cooling passages and the engine water jacket.)
Pull the plugs and "read" their condition. Give it a tune up (plugs points and condensor) and put 'er to work. If you pull the tank to clen it, you may want to check the valve lash while youhave the tank off.
Finnal, invest in a factory shop manual, a parts manual and an owners manual. They are usuually reprints but they have a wealth of info found no where else. In my opinion the IT manuals, while useful, are not as good as the factory manuals unless you are an expert on these old machines.

hope this helps you.