You can go with the volvo regulator ,it looses the vacuum line but there is no major affect. We have replaced alot of these with the volvo regulator and it works great with 1/2 the cost. If fastlane cant help you e-mail me and I will get you one.
Mercedes Technician 7 Years (retired to Hyundai)
2000 Dodge Durango
98 Mazda truck