My bachelors is in electrical engineering. I got into a part-time masters course in computer engineering. Due to work pressures and travel I dropped out. Years later with several years of diverse work experience, I got into a PhD software engineering program, successfully completed that and graduated. Both experiences at two of Australia's top universities.
I believe that my key to success was writing strong proposals in both cases and handling the interviews well. And in both cases I got adjunct teaching work as well.
In your case you appear to have a strong portfolio of work and teaching experience to support any proposal you may present. Good Luck.