Saab 9000 Headlamps

I have recently purchased a Saab 9000 CSE Turbo Auto 5 Door Hatchback 1985 cc reg. 19/9/96. I have purchased two used headlamps from another 9000, but they do not fit. They are larger than the ones fitted to my car, and the fittings are different. The ones on my car are much narrower (about 11.5cm high). They more resemble a 900 headlamp which seems to have the same fittings at the top (flat with the glass rather than at an angle). Does anyone know if my 9000 could have been fitted with 900 headlamps for some reason? This is my first Saab.
Thanks.