Any years Wheel chocks

[TJ Hopland]

They weren't the screw type of scissors.  They used the ratcheting style bar that the 70's bumper jacks used but it was horizontal and that was what actuated the scissors mechanism.  They were unique to their model in that they had different tops that engaged different areas of the specific models.  Often it was something like a hole in the frame but it could have been some other bracket. 

[bcroe]

Those bumper jacks are dangerous, I looked around
the salvage yard and found scissor frame jacks for
all my 70s cars.  Also put real spares in any car
not already so equipped.  Bruce Roe

[Eric DeVirgilis CLC# 8621]

According to a CLC member in a past post, the wheel chock (wedge) is listed in the Authenticity Manual for 1946/1947 and in another post, Barry Wheeler suggests it also was included in 1941. So at least from 1941 to 1979, maybe even earlier.  The redesigned 1979 Eldorado may have gotten the new frame jack without wedge.