I tried to go down the original path and bought one that I thought would at least look the part (being original(ish). The jack extended fine, but would not retract without me pushing down on it and then only barely. Clearly there was something broken inside it. Instead of trying the roulette wheel again, I decided to get a newer one. I ended up with a scissor jack from a 3/4 ton modern truck. It is a beast and will lift my little 3100 without breaking a sweat. Since I'm never planning to enter a competition, the lack of originality wasn't an issue for me. When I finally get my truck on the road, I plan to stow the jack under the seat.
