Few Pulsar modules make it to this time without the crystal being replaced...some were replaced at Pulsar parts centers and some left the factory with the smaller crystals. And the smaller body crystals are a lot easier to fit in there. Within a year of the Pulsar being introduced, the smaller crystals were more the norm. There were frequent crystal shortages in the '70s, as this article makes mention of(2nd paragraph).
http://www.ledwatches.net/articles/PopEle/PELCD7.jpg
Buyer beware as usual.