I'd say it's collectable now! There are people who collect powerline insulators and I highly doubt it's easy to buy/find modern ones like this. I can imagine someone having a collection of insulators displayed from the earliest to the most modern and this would be desirable for them. Good luck!
A few people might want it for their collection in 50 years, but I doubt that many collectors will be searching for this sort of thing, especially broken. There don't seem to be too many people today who are interested in ceramic insulators from 1972.