Your pictures appear to show the stump jumper and blades are in decent shape. Removing those blades would be a very tough job, but you can sharpen the blades without removing them by supporting the deck in vertical position and clamping the blades in a position to sharpen with a grinder. The primary concern is the gearbox condition. The bottom seal is likely shot and replacement is another tough job. I am running mine with a bad bottom seal using corn grease (from Tractor Supply) and filling the gearbox regularly. It is keeping the gearbox lubed but eventual seal replacement is only fix. Fortunately, these older rotary mowers have enough steel in them to do some decent repair work. The newer ones are like sheet metal.