Improving my application to Oxford? (mature student)

I'm an international mature student who is set to move to England in the middle of 2019 (I have family there). Short story: completed high school in Australia 2012. Since then, I've done one year of university part time (Macquarie University and Open University Australia) and my course average is around 75. I'm also doing an Access To Higher Education Diploma, and will sit the HAT- History Aptitude Test (the course I'm interested in is History & Politics) in October. I know I'll have to do really well in both, write a killer personal statement and obtain a fantastic reference. Easier said than done, so I do have back-ups.

Is there anything else I should be doing? Taking a complete A-level (or IAL as they are called, I think) in Australia is rather expensive ($1,000+), and I don't want to use any of the money that is in my education savings (the saying goes, once you start you'll never stop re: spending savings) plus the deadline is passing soon. I thought about taking the SATs as Oxford recognizes them, but those require years of preparation (that I know of) and may not yield the advantage I want.

I've looked on the Oxford site and they recommend taking an A-level or two aside your Access diploma. I can see why, especially for science degrees. Unsure if it relates to the course I'm interested in. Either way, I do not want to assume anything about History & Politics at Oxford.

Any tips on how I can improve my application to Oxford?

hello,

I've heard it's Distinctions in all Level 3 units for my Access Diploma. AAA for A-levels. So I'll have to work hard (and smart). As a mature applicant, it's hard to find concrete information on how Oxford will review my application. Oxford also requires a History Aptitude Test (currently browsing through 2015's paper). I did the 'Higher School Certificate' in Australia (average marks) in 2012, however as that was long ago I have since taken history modules at university and done well.

I see the benefits of taking an A-level, and maybe I should- it's just I want to devote my time studying for the HAT and Access Diploma, as well as engaging in my interest- history. At the moment, I'm not in the UK so taking an A-level would complicate things. And I don't think you can take A-levels in Aus, just 'IALs', which I don't know much about and they don't seem to be equivalent.

In that case if you are likely to meet the entry requirements with your access diploma then I wouldn't worry about doing additional A levels and focus on what you do need to do like you say.