4
Darn, sorry. A couple of other suggestions that may work if modified are:
Resmanager
https://xoops.org/modules/repository/singlefile.php?cid=102&lid=1398
A Slot Management System 1.2
https://xoops.org/modules/repository/singlefile.php?cid=92&lid=1348
MRBS
https://xoops.org/modules/repository/singlefile.php?cid=109&lid=1189
Event Guide
https://xoops.org/modules/repository/singlefile.php?cid=109&lid=1556