Well, I've just wasted an hour looking for an answer to this General answer is that if assets are discovered after an estate has been closed, the estate is re-opened and its value recalculated, because there could be tax implications and so on.
In this case, though, the asset is valueless, in monetary terms. But I can't see any simple way in which the company (club) can cancel them. Nor do I think that someone could simply write in and say "I'm snorbens' heir - you can have them." As far as I can see, there has to be a properly-authorised legally-recognised personal representative of the deceased before anything at all can be done.
OTOH, this must happen all the time, so there must be well-trodden ways of dealing with it. I'm sure that someone here can tell us.