Over the last 10 to 15 years or so , whenever I went to swap meets, I looked for Robart incidence meters, because I found that having 3 was pretty handy for setting up a an airplane and I like have spare tools of any kind. I could get them in the $5 range most of the time and don't think I spent over $1o for one if it was in really good shape. In recent years, swap meet participation has really dropped off and I haven't seen one in a long time. Does that mean all the good stuff is gone!!?? The extruded bar stock for the rail might not be hard to find or substitute something else for, but making the pieces for the leading and trailing edges can be tricky I think and they need to be exact. I would hate to try and build an airplane with out them, one for the power plant, one for the wings, and I sometimes take the gauge off the rail to put on a flat stab or use one of those little square levels that weigh almost nothing. I just checked the Robart web site to see if they were still made since Robart announced they were eliminating some items from their catalog, and they still show it, at a $60 price tag now but is shown as Sold Out. their new Version 2 ,which is just the mounting bar with a cradle to hold a cell phone is also shown as Sold Out. I can't imagine putting a heavy cell phone on one of these at all, they need to be light, in my opinion, in order to function as well as possible. The little digital meter is nice, look way lighter than a cell phone!! If you can't get any of this stuff, it's back to drawing a straight line with a pen and then measuring with a ruler!!