I have a first-generation Lego Pneumatic set (nr 8851) that I recently took out of storage. I remembered from the last time I built the set that the pneumatics weren't working and I just confirmed that this is still the case.
After some experimentation, it turns out that the pneumatic distribution block is not doing its proper job of providing pressure only on one outlet and suction only on the other outlet, so it seems to be broken internally.
My question is, given that this part is specific to the first generation pneumatics and has been out of production for over 30 years, is it worth it to look for a replacement of this part, or is it to be expected that due to the age of the parts, the internals have deteriorated to the point that I need to be very lucky to find a working one?
Another option I am willing to consider it to try to repair the piece I have, so any advice in that direction is also welcome.