Relevant postgrad work experience (history of art)?

I'm studying for a postgraduate certificate in history of art at the open uni at the moment to prepare myself for applying to a masters next year (I had bad scores in the final year of my degree due to bad personal circumstances that have long since resolved and I'd like to prove my actual potential now and get to where I always wanted to be- doing art history).

I work in a design job and finished my design degree years ago (I'm 30) and need to continue working this year alongside my studies. I notice a lot of places I want to apply to are keen on me submitting a cv and personal statement which include relevant work experience. Whilst a job in web/graphic design isn't MILES away from history of art, it seems too far for them to consider it, and that actual history positions in museums and galleries are more relevant.

Any tips? Should I try to figure out how to get at least some experience, even one afternoon a week, in a local gallery or is this a bit contrived now? Any other ideas how I can prove my commitment to art history, as I've no idea to show it other than saying 'I have always been obsessed with it and have spent time and money I really don't have to get onto this course even though there may well not be a career at the end of it, just because I adore the subject'

Are you sure they are really interested in HoA work experience? I would have thought making that any sort of requirement would severely limit your applicant pool given a) the number of roles in HoA and b) the number of roles that don't require a Masters degree! I suspect what they are more interested in is discerning applicants with workplace skills such that they could actually go on and hold successful careers with their degree, rather than encourage diletantes (SP!) and drifters with no specific aim.

For mature students, a CV often discloses attribute the applicants themselves can't express, the independent thinking, analysis, self-motivation etc

I can't be sure on that without reading the actual wording, but having worked with PG recruitment and HoA departments, I would imagine that is why a CV/work experience is asked for.

Thank you so much for your thoughts on this, it's helped me panic a little less.

The wording was:
"A CV/résumé is compulsory for all applications. Most applicants choose to submit a document of one to two pages highlighting their academic achievements and any relevant professional experience."

Which freaked me out because I don't have any relevant academic achievements/professional experience apart from my Postgraduate Certificate, unless they are happy to count graphic design as being relevant.