I usually just look at it. A polished eye can tell if it is low. However, you will need a port for filling them, so I think that is a good idea to build something like that.
If you don’t like “eyeballing it”, like I do, here is something you can do to measure pressure without putting a gauge on the stem.
Based on the fact that the tire-contact-area (sq in) X tire-pressure (psi) must be equal the weight on the wheel, and you know the weight on the wheel from your W&B, you can put a piece of paper under the tire and at different tire pressures draw a pencil line on the paper around contact of the tire to the paper for each pressure. Label these outlines corresponding to each pressure (you just need to do this once). Then take this paper to a xerox and make a bunch of copies. When you want to check the pressure, just roll the wheel onto a fresh sheet and check the size of its “footprint”. That will tell you the pressure.
2 things on my mind today.
First.... I attached some pictures of the little saddles I epoxied above my axles to help line up the axles with the holes in the wheel pants.
It's a snap with the airplane upside down, probably have to use a small jack under the tire to hold it up when it's right side up.
No jiggling around any more.
Second....What are you doing to accommodate checking and filling the air in the tires.
I'm thinking of drilling a hole large enough on the outside of the wheel pant to get the gauge/ filler in.
Somewhere between 3 and 9 o'clock low. Any recommendations?