I'm in the process of installing the 1-1/2" hydraulic pressure gauges at the front end of the cockpit tunnel in my L-235. I tee'd into the two lines under the pilot seat and ran some 1/4" 5052-O tubing diagonally up into the tunnel. I knew from experience that when I needed to end up with two short but multi-bend pieces, I should order twelve feet of tubing; So I did.  I must be getting better after all these years because it only took me two attempts to bend and flare the low-pressure piece with three bends, and three tries on the more complicated high-pressure piece with four bends - and I still have six feet of tubing left! LOL!

You can see in this photo how I had to stagger the gauges to avoid interference with the elevator push rod and stick crossover weldment underneath. I also had to flush-mount the gauges so as not to interfere with the primer pump. I covered the gauges with blue tape and Vaseline and used them to mold the flox closeouts for those 1-1/2" holes. When the tunnel cover is painted, this installation might actually look semi-professional!



The high-pressure gauge was more of a problem because I had to use a 90° elbow on the back of the gauge to keep from hitting the elevator push-pull tube underneath. Thankfully, it looks like it may all work out when the $35 AN916-1 brass elbow arrives from ACS. (Why the heck do AN brass elbows cost so much???)