what is on front of engine on the block that could be leaking oil. Oil sending unit, camshaft sensor and what else?

 

hey steve I don't have the same year car as you so I won't be much help visually trying to find your problem but anytime I have a leak of anything I go buy a small bottle of uv dye made to change the color of oil, trans fluid, ps fluid or coolant and anything else that's leaking. the bottle you get needs to say oil on it and usually cost around $9 in California and it's no bigger than a bottle of pocket hand sanitizer. Just poor half the bottle in and look for the leak it says you need a uv light and glasses but I never use them cause it makes the leak bright enough to see without them and plus the light and glasses are an extra $20 which I paid but you can see the leak almost better without unless your working at night in the dark. Hope this helps

 

Front main seal.