I can break it down in sections for you.
The Lid is correct for 1968-Some 1972 289-302-351W-351C and 68 390 2v.
The Base-Bowl with the Plastic Breather Fitting is 1970-Some 302-351W and 351C but the Cleveland had a Vacuum Switch mounted the flat spot inside above-behind the carburetor opening. There were 2 small holes drilled in that flat spot for the switch. The 68-69 Base Bowl is the same except it had a Metal Breather Tube instead of plastic.
Also 1970 302 used a different base-bowl then 71-72 because the breather fittings and holes in the side of the base are in different locations depending on year. I have one of each listed in my store if you want to check them out. Click the link in my signature.
The Snorkel is Correct For Late 1968-Some 1972 302 and 1969 351W. Early 68 had a Vacuum Motor on bottom of the snorkel.
I didn't see pics of the heat riser but will be specific to 302, and probably a 70-72 version. Each motor had their own specific heat riser.
Overall that Air Cleaner Assembly is Correct For either 1970 302 2V or 71-72 302 2V. .
1972 was a changeover year for small block air cleaners and I'm not sure if both styles were used simultaneously or if it was a direct changeover. This style of Air Cleaner was discontinued in 1972.
This is All To the Best of My Knowledge. Andrew