This is a "ribbon" speedometer from a model 93 or early 96 Saab. The photo below shows how the poor thing looked when I took it apart---YUK! After I took it completely apart, blew the spiders out, cleaned out the rust and general crud, it began to look a whole lot better.
I painted the case--inside and out--and polished out the badly scratched plastic "glass". You can see that the odometer is reset to all zeros plus point four miles--the last number wheel is for tenths of a mile. I even replaced the colored plastic for the indicator lights--seems like those litle buggers are always shot. The small one right under "SAAB" is red, the larger one below that is green. So this remnant of Saab antiquity looks and works like new once again--it's ready for another 50 years of faithful speed-O-ing. Old Trolls are like that.