It would be much more difficult to replace the Bird at any time in the future than it would to replace anything else (Home, Ex-Wife, furniture etc). This is something you started for yourself, and something that you know inside and out. The feeling of getting it back together and being able to take it out and enjoy it is priceless.
I agree, I think your well past the halfway point and you could do just what you need to do to put her back together and get her back on the road so you can enjoy it for a while. Then you can finish things up as time and money allow. But something like that, you couldn't do again for what you have into it... you deserve to see it through and the benefit of enjoying it for many years to come! Good luck with everything!