The hydraulic lines have numbers that correspond to the ports on the cylinders. If you have them they can be rebuilt for about $50 each, may be a bit more these days. However if the controller is "fried" that's an entire different matter.

The roll bar possibly could be deployed manually, then it is always up and no safety risk either.

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If you do not have the factory service manual, it is available online at benzworld dot org, in the W124 Class section under Sticky 124 DIY thread. There is a Cabriolet owner's manual supplement there I think.

Good luck.

IIRC tophydraulicsinc.com charges around $55 each plus shipping.They rebuilt mine and I was very happy with the rebuild. I made the trunk and interior panel removal DIY and at the time used some threads from here and benzworld on removing the cylinders. Which could help you for checking connections and lines.