I'm busy with upgrading my C172, and thought I would post some pictures here because it really is an avionics package that belongs in a Mooney.
The GNS480 is still a very capable WAAS GPS for future ADSB and has tons of serial and Arinc ports to communicate with all sorts of devices like ELT, transponder, ADSB, HSI, and more. The Sandel is a great way to save panel space - combine DG, ILS, ADF and much more into one locate without spending 10AMU's on hardware.
Keep the KR87 ADF, but get rid of the indicator. Integrate your DME. Get rid of your stormscope and replace with remote WX500. Replace transponder with remote SL70R or new GTX32/33
I used a 3" JPI engine monitor with fuel flow just so it matches, looks great. SN3500 shown in the panel, but thats for my other plane. Hole is for a KI258, same as KI256 without the FD bars. Panel is cut from 0.090 2024-T3 on my AXYZ CNC router. Still learning, will have to cut a couple more times. (You can't rely on the manufacturer's cutout dimensions, they suck).
Apollo GPS MAP is just for show. I think I should put the ADF and ILS indicator down at the bottom, and move the JPI up?
Don