Classic/Antique Car Repair: MGA transmission, clutch plate, clutch disc

Question
Hi:

I have a 1958 MGA 1500 roadster, that has been sitting for quite some time (almost two years). I had it serviced recently, and the mechanic told me that the clutch plate was stuck, but he freed it. That was a couple of months ago, and I have since driven it only once since. Now, the clutch appears to be stuck again. When I try to shift, I can't get it into gear, and it grinds loudly. The clutch pedal seems to be okay (good resistance). I need to check the transmission fluid. Do I use just regular fluid, by the way? Also, any advice on how to get the gearbox working again?

Answer
Unsticking a clutch plate is not rocket science. I usually place the transmission in high gear without the engine running. Then with my left foot on the clutch and my right foot planted on the brake pedal crank the engine over. This will usually free the clutch disc. The transmission and final drive on your car will work very well with 90W gear oil. In cold weather a lighter oil such as an 80W is recommended.