I'd check with some auto parts stores or hardware stores that carry
Hydraulic oil. If the viscosity is the same as what you top systems uses
it might be okay to as a substitute oil. You could always drain it out
and replace it with the more expensive Saab oil later.

My 68 Buick service manual states Type A Transmission fluid was acceptae
to use to top off the fluid level in the convertible top hydraulic
motor.

You could also ask at a convertible top shop what they would recommend
using.

Good Luck


harryface
2005 Park Avenue 60,013
1991 Bonneville 309. 739