It seems a long time, but I can see how it would take that long if he was trying to do it all himself.
Thing is, the creative process and mindset is a different set of skills from what it takes to produce something. Not that one person can’t do both, but it is harder and takes longer.
What needs to happen is to hire an editor for a few weeks to help Jo get everything together and select what is to be published, then Jo can let it go and the editor can see it through. Could do that on kickstarter, would likely need to find an editor first that had done that kind of thing before, and they could price the whole thing up.
It’s not rocket science, strips are published all the time.