Those are the same air assist struts as used on the Riviera. I have a new set of those in the garage, Monroe 71801 is the part number. If they have them in stock, may want to buy. I picked up the last set on Rock Auto for $41 per strut. They will work but may need to do something to lightly pressurize the air bladder when in use, or cut it off.
The Reatta never used an air assisted strut, straight damper strut only.