Eco Air Meter Help

[bergy]

I picked up a really nice, original Eco Air Meter a couple of weeks ago. I disassembled it & polished up all of the red painted parts. The original paint shined up nicely. I'm posting here in the hopes that one of you have worked on an Eco Meter before & can offer some words of advice. Questions:

1. There are 3 air ports in the picture. the left one has a needle valve in it & I'm assuming that it adjusts the frequency of the bell ringer when the tire is being filled. There is a small port in the center that take a compression fitting - I believe that it is for the "air in" - is that correct? I believe that the port on the right is for the "air out". Is that correct?

2. I've greased all of the gears and bearings. Also removed all of the air fittings and cleaned the ports. Is there anything else that I should do before trying to put pressure to it?

There are lots of restored Eco Meters out there - I like the idea of having an original (albeit cleaned up) original one.

Any help would be appreciated.