slightly off the wall search for maths tutor/study buddy

[MamaLaMoo]

I'm looking for a maths study buddy but ?.. I already know a lot of maths.

I am at home on maternity leave with DD2 and need to do something to keep the old brain ticking over. Have a PhD in theoretical physics but have some gaps in my knowledge of various degree level maths topics and want to learn more group theory, differential geometry, topology etc.

Open University courses in maths are not covering what I am looking for or do so at a level I know. Local tutors do up to A Level but I live near Oxford so could try and find a tutor for uni level stuff but I'm not sure how to go about this.

Does anyone have any suggestions how to go about finding a study buddy or tutor?

The university of the third age might be an option - its in general for older people but if you are not working can usually join in classes - my dad - not in oxford - did a course called the maths you forgot
or look on gumtree or some of the tutors website -first tutors - some people do adults tutoring - or advertise on gumtree maybe?
or ring maths department at oxford uni and ask?