Given your background, I think you will be an exceptional candidate that some schools would actively seek out, and could do favours for. The obvious question here is: will Oxford let you resume, transfer to their full-time MBA or give you an intermediary credit-bearing award. With your Oxford transcript, there are also some accredited MBAs that have 'top-up' options, like Essex and Northumbria. I also wonder about programmes aimed at students who have completed part of an MBA, like the MSMS at the Sloan and Marshall Schools.

The other option for you to consider would be alumni-status executive programmes, which would allow you to not repeat the core courses. It depends on your career goals.

Otherwise, many schools are more flexible with the GMAT. Even top schools will let people in with low GMAT scores if they show promise elsewhere, on case by case basis.

That said, also see http://bit.ly/WhyGMAT

Edinburgh is a good school. Strathclyde might be interested in you as well. If you're specifically looking at schools in the UK, I know that Manchester will let you take their own admissions test, in lieu of the GMAT, if you interview on campus.

But Duncan's right, perhaps you should discuss with Said what options are available to you. If they took you on at one point, they might still be interested in you as a candidate. It wouldn't hurt to just contact some higher-tier schools as well, with your profile info, just to see what they think your chances would be.