Looks like a good working mower and a lot of spare parts ,the reel may need sharpening and check / adjust the bedknife.
Think of the reel mower cutting action like scissors; two blades coming together, with light contact, to cut the grass. Without sharp reel and bedknife edges and properly maintained, light contact, the reel mower will not cut the grass and give a good quality of cut.
There are a lot of youtube clips showing how to sharpen the reel ,I've even seen a reel sharpened in a lathe.
Otherwise you can get the reel professionally sharped at a shop if it needs to be.
