Are these pure brake levers, or brifters? (brake-lever + shifters)

If they are pure brake levers, I personally would not pay $50 for some rare NOS hoods. You may need to improvise something. For example get Cane Creek hoods and cut off a little to fit around that lip that tricolor levers have.

If they are brifters, maybe these:

https://www.amazon.com/SHIMANO-ST-66...8CZSM1X6G7ANMK

As mentioned above, Shimano has historically changed their standards like every 6 months. This forces people to buy new complete levers (or other parts) when a consumable part like a brake hood wears out. It's a pain, but it is what it is. The short answer to this question is, no, Shimano vintage hoods are not interchangeable.

Most likely someone here has had and solved this issue, but you may need to bump the thread once or twice.