I have read a number of posts where people have made attachments from hockey pucks to place under the frame at the jacking points, and then to use a trolley jack with them in place. I was lazy. I decided to use the stock jack from the truck in between the frame and the trolley jack.
This way the round base of the trolley jack doesn't damage the 'frail' Fiat's frame.
I will try and post some pictures but not sure how to do it from my phone.

 

Do you mean you took the Honda scissor jack that came with the car, and placed it atop the lift pad of the trolley jack? Simple solution. Did it work out well?

Not to change the subject, but depending upon where one lives, what you are calling a trolley jack may be elsewhere called a floor jack, or a rolling jack, or my own personal preference, a rolling hydraulic jack. I think trolley, for anything that one rolls around, is chiefly British. Canadian English?