vaccuum gauge air valve

So, I have a set of vaccuum gauges that use those little plastic valves to dampen the needle... anyway, my buddy borrowed them and removed the valves...and now they are mia. Where the heck could I find some more? Think an aquarium place would have some? They remind me of something that you would use for a fish tank...

The dampers are just a plug of anything - plastic, wood, etc. with a 1 mm hole drilled throught the center.

You can even just use a locking clamp mechanism in the mean time and slowly open it till you get response. Basically it just makes a very small opening in the line to reduce reactions in the guage to the pulses. Should be as close to the engine as possible.