I have some recent experience in this matter and I have some tips:
- try very hard to contact the maintainers, original creators, and anybody else who's ever uploaded a copy. Learn from PAUSE which user ids have admin and which have write perms and contact all those people.
- post somewhere about your intentions to take over the module, somewhere high profile, like this site. You'll get frontpaged, and you'll maybe attract some attentions of people in the know.
- After the above, go ahead and post to the list that you wish to take over. It'll take a month, so...
- Be really polite, respectful, and persistent. Check in every week. It's slow, but it works out in the end.
Woah, I missed the part where you don't have time to maintain it, before I started blabbing on and on. That's the biggest problem with any module with lots of tickets and patches. Choose to be the guy that makes the time to apply patches and upload, it's worth it. It's just a couple hours here and there and you'll save someone some headaches.
If not, much of the above still applies, I'm sure.