You have an old style oil bath air filter. Dump the bottom pan full of oil and leaked in water, spray clean or wipe it out. no replaceable anything. Fill with clean 30W, or even hydraulic oil up to about the 1.5 in mark, reinstall and tighten the band clamp well.
the drum bearings are sealed and have no grease fittings. there were a couple zerks on the clutch housing, and on the leaf spring mounts.
Aside from the engine dipstick and radiator, check the oil level in the governor. Top plug is a filler, center plug is the level. There is also a fuel filter in bottom cup of the fuel pump.
Look over all the belts, and the radiator hoses for bad spots.
Mine vibrates so much started using blue locktite, nyloc nuts and grade 8 bolts for repairs.
Open up the drum housing and spray all the recessed allen bolts, from both ends of the through holes, with Kroil or other penetrating oil. When you have to change the blades it will give you a head start. the blades should be reasonably sharp, straight and free from big nicks. you really need to fire up and run 20 branches through to see how it feeds before looking for blade and bed knife problems. Good luck.
Also, I found vin plate attached inside the front frame rail, and vinnum welded onto top of LH front frame rail. Models in 1970-80 were JEX, JEY. Both these manuals are similar.
