It was actually much more straightforward than I expected so here's a quick rundown of the changes:
- add two columns to the jos_eventlist_dates table to hold the scores
- add them to the class by editing components/com_eventlist/eventlist.class.php
- edit the sql statements in components/com_eventlist/eventlist.php and add in our new columns
- adding input boxes to the admin interface to administrator/components/com_eventlist/admin.eventlist.html.php, just a couple of input type="text" boxes
- adding a new column to fixture lists in file components/com_eventlist/eventlist.html.php (not taking account of the lovely flexible width administration tool in the admin interface) and putting the results into each row
The scores default to 0-0 and show as 0-0 when there are no results - netball doesn't really finish with no goals scored so its safe to assume that this means no result in this case! Last weekend our match finished 40-28 which is about average.
Hopefully this is interesting or useful to someone - if nothing else it will remind me what I changed next time I come to do something similar or further modify this!