How do you jack up a Curtis Wright/Early Airstream?

I wanted to jack up my Curtis Wright today to take a look underneath. I remember that the guys that put temporary used tires on it at a tire shop had trouble getting the CW jacked up. There doesn't appear to be a very sound place to put the floor jack. I believe the tire shop just put the jack under the leaf spring bolt and crossed their fingers. Turns out that the tire was a little too wide to slip between the hub and the fender skirt. They tried jacking the axle but no luck. The tire wouldn't fit. I thought about flipping the axle but that seems to be a whole new can of worms. How do you guys jack up old tube frame Airstreams or CWs? Thanks for any tips. Chris