For those who want to continue to fly the old Microsim T-37 "Tweet" in P3D, I have modified selected panel folder files and xml code to bring most of it to full function. Simply replace the "Panel" folder with this one (after making appropriate backups), and all gauges work. Panel is still not clickable, and the fuel quantity gauge has been replaced with one of nearly identical capacity - Pierre Fasseaux's freeware offering from "simviation.com". Thanks, Pierre!
Attenuators work automatically, systems that no longer work have been bypassed (fuel management, for example - both engines now run on all tanks until dry). I have slaved both the RMI and the TACAN/DME digital readout to the nav radio frequency control that can be brought up by selecting from the 2D panel menu, or simply hitting Shift+7. Use your mouse roller to change freqs.
This panel fix works for the earlier of the two releases of this beautiful old Tweet. If there's enthusiasm to get this baby up and running again, I'm sure we can collectively get the later version running, too (has a slightly higher-resolution VC interior model).
See you back in the glory days of Phase One UPT!
Rhino