When to say when with a project car....

If it's the car you want (and it seems to be so for you) then don't; I repeat don't sell it.
Your situation kind of sounds a bit like what I was faced with 20 years ago and for me, it's still not on the road.
Short history lesson: I found my dream car some 20 years ago. Smashed up, all glass beat out, parts missing, tires flat, car filthy etc. etc.. In spite of all the (bad) it was solid and love at first sight. I too didn't have a garage nor tools with which to do the body work nor the experience to do the body work.
I did, however, have enough love for the car and determination to want it in a garage and have the body work done. First the garage I found (cheaply-just to keep it under cover and out of the elements) and next, I bugged the heck out of the local community college to take it on. I really kept going back and back to them to take it on. After much begging for them to at least come and see it, they (he) agreed to take the project on providing I round up the glass and body parts that were smashed up.
Fast forward almost 15 years and much unemployment and underemployment later. Still the desire and love for the car (it has had the body work and paint job and still sits in a garage). Some large "other" projects need tending to like fixing the house, having a family vacation we promised ourselves and a daughter getting married. Now it's my turn. I have the car, I'm 20 years older, have the desire and a few bucks to put into the car and... it seems not enough time. I do have only two choices in my life for this car..... Finish it or die! It really has kept me going with the dreams I have of driving it through some lean times.
Sorry to be so long winded. Bottom line; if the car means as much to you as mine does to me, you will find a way.
Thanks for the opportunity for me to re-commit to my car.
Cheers.... Paul