Forks can be found. There are new ones, there are used ones... was that really the question?

I'll let someone else tell you how to measure your frame to determine the dimensions of the desired fork. My advice is find any kind of fork that looks like it might fit --borrow one from another bike, for example-- and fit it. Then check if the top tube is level. Check if there's toe strike. If the trial fork isn't perfect, you should be able to estimate what it would take to make it better; so come up with the dimensions of the fork you want. Then... hope you got it right.

My Lambert frame came with a fork; but of course not the quick-release aluminum "death fork." Just some chrome thing. With that fork, the top tube sloped downward from the headset to the seat. The fork legs were too long. l fixed this by changing the rake of the fork (bending them a bit). This enabled me to figure out what I needed, and to ride the bike; I eventually found Electra was selling a fork with pretty much the exact specifications needed, and I got one. Fit perfectly!