I think I can add something to this conversation.
I did the same thing as you - I took a couple years off after high school and worked fulltime. I eventually went back to community college then transferred to a state school and graduated this summer (at 26 years old). I have sketchy undergraduate transcripts in general (GPA is ok, but lots of withdrawals, etc. because I was so focused on work). I solely went to school at night while working fulltime.
I was invited to interview at HBS this fall. Definitely a surprise, but I hope you take that as a sign that your nontraditional route does not rule out top MBA programs. I like to think that HBS was intrigued by my differences, rather than using them as a way to rule me out. Obviously, the interview is far from a guarantee that I will be accepted, but it's a good sign nonetheless. Hopefully I can give better news this winter that I am matriculating, but, regardless, I would use your different route as a reason for admission, rather than something to apologize for.