Left my "difficult" advisor. What now?

I am a STEM grad student, 3 full years in and currently in the middle of qualifying exams. In May, I switched advisors.

I am one of a long list of grad students who failed to be able to work with my previous advisor. (And I believe I will be the last, as he is now prohibited from taking on more students.) My department is being very supportive, and my new advisor is wonderful.

The problem is that no one at my university does anything close to the subfield my PhD project is in - so now I have a significant expertise gap on my committee and in my project supervision.

However, I love my project. It is what I came to grad school to do and the reason I didn't leave my advisor for so long. I was determined to stick it out. A key reason I decided to leave my bad situation was that several faculty told me privately that the department would support me to continue my project with other supervision (external if necessary).

But now that I'm talking to potential collaborators and looking for external supervision, I'm worried that it may have been wishful thinking. I think my department is familiar with my previous advisor's conduct and assumes everyone in his field is as well. But even if that is true, and I'm not sure it is, other PIs still may not want to get involved with me as it would cause significant tension with my previous advisor, and he is quite well known.

So here we are. My options:

- Quit/master out and start a new PhD somewhere else. I've had my master's for a year now through the same program, so I feel I would just be quitting. Starting somewhere else, I could be upfront about my extensive experience and desire for a "efficient" project. In the long run, it would set me back a few years, but I would learn a lot more. I'm increasingly thinking my old advisor may be a charlatan. He really didn't teach me enough. But I can't imagine starting a PhD over again at a whole new university. It is making me cry.

- Rush graduate with a PhD. Some faculty have told me that I am far enough along in my project that I could simply write up what I have done and graduate. It may not be a good dissertation, but it would be enough if what I decide I really want to do is GTFO. But I want a research career, and that means publications. Not sure that is feasible.

- Start a new project at my current university to add to my dissertation, strengthening it and my credentials. But like I have said, no one at my university is doing something close to what I want to do. I came here specifically to work with my previous advisor. This option feels like a waste of time to me right now.

- Continue on old project. Possibly with external leadership, but at minimum, I want someone on my committee who works in the subfield. My preferred option. I want to finish things well, tie up some loose ends, and turn my work into publications. Pipe dream? Possibly.

What would you do? Which of these options seem completely infeasible to you? Anyone have comparable experience? Please, I need advice.

I understand my career goals factor largely into this. I am looking to stay in scientific research, ideally a national lab setting. I don't want to become a professor, but I would consider working at a university in a research faculty position. No matter which option, I am probably looking to do a postdoc at an institution of greater standing than my current one.

Also maybe important to consider is that I haven't published any of my work so far or secured external funding (grants, etc.) due to my previous advisor discouraging or prohibiting me from doing so.

Previous advisor thinks I am a pawn in a political attack against him and is not cooperating (has not even agreed to meet with me since he was informed of the switch). However, I've been assured by multiple university admin levels that I have the right to proceed with my data and results.