Thank you for your reply.
You are correct, there is a cap on the shroud. It is still there but not attached to the spreader. I thought it was a protective cover, but it should have kept the shroud on the spreader. I will investigate that option when I get up the mast next weekend.
The cap you mention is most likely a spreader boot. These should not be relied on to secure the shroud to the spreader. The cap I refer to is usually aluminum and exactly the same shape as the end of the spreader. It's held to the spreader usually with two allen head cap screws. These don't usually require the use of a protective Spreader Boot.
It sounds like you have the kind that would be seized on. Under the Boot you see still attached to the shroud, you will probably find the remnants of the seizing wire.