I think you may have gotten some incorrect information somewhere along the line. This model number, 555975, is for a Mark V Lift Assist, implying conventional headstock. The PowerPro Lift Assist for Mark VII's and Mark V's after 1972 is 556191. More importantly, the replacement gas cylinder for PowerPro is 556199 for $47.34. See: https://www.shopsmith.com/ownersite/cat ... assist.htm I don't have a lift assist, but I'm under the impression that the PP version has a quick disconnect which is to make it easy to disconnect for under table ops. That is probably not going to be on any aftermarket version you find.DAVC3 wrote:Your photo matches the Lift Assist on my machine. I upgraded to the Power Pro and got the Lift Assist because the headstock weighs more than the conventional one. The model number is 555975.
If you still want to pursue aftermarket, I'd look for manufacturer markings as a starting place. I don't see a modern car parts store being much help on this. You are going to want to match by extended length, compressed length, and force. They are going to want to match by Year, Make, and Model of the 'car' yours came off. I've been in exactly one parts store in the last 30 years that had what used to be called a counter-man that knew this kind of stuff. But there are many sources available based on the lengths and force rating. (I'm thinking the force rating for this one must be very high, it does not have great leverage.)