Nice! Are you doing the work yourself under supervision or is an avionics shop doing the install? Just curious if 4 months is the usual amount of time for an install like yours...
Well, the painting is allowable owner maintenance (I'm not touching the balanced control surfaces and based on Part 43: Apply preservative or protective material to components where no disassembly of any primary structure or operating system is involved, and where such coating is not prohibited or contrary to good practices; Cessna cowls are just held on by southco twist fasteners...certainly not primary structure, no disconnecting prop, just unfasten top and bottom and lift off. Nothing attached to it, nada), and the avionics work was done under direct physical supervision and observation of an IA (I hold a GROL FCC license, fwiw), who did the heavy mechanical (riveting, tensioning and rigging cables, running the harnesses, and will do the ifr cert, &c., &c., &c.), and I did the design of the panel, had it cut by Skyhawk Panels (I see the story about the gentleman who I used in the current issue of the Cessna owners society magazine...lol) as an owner produced object which my IA approved of. Lots of back-and-forth, etc. And lots of wires.
Is 4 months usual? I don't know; I'm into this (both finanicially and physically) pretty deep considering that this job encompassed:
1. Rip out existing instrument panel, vacuum system, hoses, radios, existing harnesses, and seats, front side panels, rear bulkhead panel, carpet, A pillar trim.
2. Send out pitot-static instruments for O/H and recalibration.
3. Design and contract for production of panel replacement.
4. Order all the Garmin stuff: 2x G5, and GFC500: roll, pitch, autotrim servos and control head.
5. Wait for all the bits and pieces to come in.
6. Perform an annual inspection.
7. As the stuff comes in...start building the systems in parallel with IA building harness and interfacing to existing radio stack wiring.
8. "While you're there..." replace 50 year old RG58 antenna cables, where necessary, with fresh RG142 double shielded teflon-coated coax for the Comms, Xpdr, Marker, etc. (I had already put in fresh cable for the 430w and from the nav whiskers in '18 when I did the avionics upgrade.)
8. Troubleshoot dodgy connections (when you're connecting over 500 wire ends...you're bound to have a couple...a good VOM test meter is your friend).
9. Since the whole plane is pretty much open more than normal, give it a good coating of Corrosion-X, especially in the wings and tail, and up the rudder and in the control surfaces.
10. Other stuff....like painting and retrimming, and reassembly of the interior, and ...
Yeah, I could take less time. Luckily, I'm a CFI, so I get to fly anyway; would I like my plane back and done? (The avionics guy/IA broke his foot just before starting to configure up everything...so, right now, waiting for him to be able to finish it up...and airport owner would like to get his $$$) Yeah, it would be nice. But, in the end...it's a BIG FREAKING job to get it done...and I don't think that 4 months, in the general scheme of things is out of line (ever do an engine overhaul? Takes about the same time, unless you buy a ready-built from PennYan or ? and just swap out...talking about a field overhaul by a competent AP...).
(Now, don't talk with me about doing a fabric headliner in a Cessna. For such a simple job...it will take you at least 24-32 hours of tugging, pulling, scrunched up in a hot cockpit...never again...)
But...got the cowling all installed:
Got to put it on this way to get the mask lines for the red and blue stripes which will terminate at the nose cap.
Of course, when you go this far...(yes, I know there is a paint crack...this is a clean-up, not a restoration), always nice to use fresh stainless fittings.