Rear seat access gas springs

I get a lot from this forum and appreciate the wide range of knowledge and detailed discussions but I’m struggling to find the answer to this.
I have a 2000 196 SNCB with a rear storage access over the gas tank. Rear seat back lifts up. It is missing the gas springs that hold it up and I’ve been using a 2x4. From what I have found online it looks like a 17.2in spring is required but after trying one I don’t see how it can work. It’s too long and the spring cannot be compressed enough to attach it. The distance between the two ball stud supports is 14in when the seat back is fully extended so I would think the length should be about 14in. If someone is familiar with this or has a functioning rear seat back access could you take a look at the springs and let me know what size (length and pressure) they are. Thanks, any guidance is appreciated.

You've got it right, if max distance is 14" when open you need a spring 14" long when extended.  Try to get the dimension when closed, I know it's an estimate but if you use a tape and get the number when almost closed you can come pretty close.  I looked at my Sport Nautique trunk, has dual shocks and I think that 17" you found it what I have, around 9-10" closed.  So you just need a smaller version, should be easy to find.