Quote Originally Posted by MDR View Post
New lubrication. A short time solution is to put the shutter on a radiator for about 15minutes, the dried lubricants will be liquid again and work. It's better to change the lubricants (suitable for cold weather) though as you will have the same problem again if you use it in the cold.
No, don't do that. The OP says that "...they don't open at all, or open unevenly..." which indicates there is probably more wrong than thickened lubricant. Possibly the blades are not engaging properly with the actuating ring, or something was damaged by drag caused by the thickened lubricant.

Do it right, do it once, have a reliable shutter... try home made half-baked repairs and have potential junk. This shutter is nearer 50 than 40 years of age at a minimum, possibly it has never been serviced.