No upshifting on 91 300SE
 

I changed the filter and took the valve unit out and cleaned the two liitle screens in it, but the car still doesn't shift out of second. No metal shavings found. It only downshifts to first if I put the lever all the way down to 2. I assume it's stuck in 2nd. At 3300 rpm it's driving about 25-30mph. The car is in great shape and only has about 140-150K miles on it.(odometer broke last year) I'd like to try anything I can do short of removing the trans to save the car. I understand it may be a bad governer or valve body. Is that the probable cause?
Can you guys tell me where I can buy and what price these items should cost? Also, what model trans does this car have?
Sorry to start a new post, but old ones sometimes don't get answered.
Thanks

Also, i never checked the vacuum to the transmission. Can that cause it to not shift up?

3d question- I found an inexpensive 1990 300SE that needs body work. Is the transmission the same in the 1990 and my 1991?