Ainsley,
I presume you had "no hits there yet" on GEDmatch because you just uploaded. It takes hours to process your data and produce matches, so I'll bet you have TONS of matches there by now.
Of course, it would be more helpful for this particular project of yours to have your dad's DNA on there, too. Really, yours won't tell you anything that his doesn't.
Be aware that you can also upload your dad's AncestryDNA data to MyHeritage for free, up through 18DEC. The more people to match against, the better, so that's a "no Brainer".
Also, I'd be interested in hearing how strong his top few matches are - measured in centimorgans (cM). Chances are, we can tell you what his possible relation level to those people are (such as "1st cousin", or "half-sibling"), and that would tell you a LOT.