So, here's my thoughts:

Primary will be the Aspen E5. Mostly, this is for the HSI, but eventually I will probably upgrade the whole thing to a MAX.

The AV20 is much more than an AI (although that could be very helpful). It does a bunch of air/data computations and gives density alt, TAS, and it will give me AOA and G loading. All for $900. Easy pick.

Last one is the original from Cessna. It needs to be retained until I dump the 400A autopilot, which will happen when A) mine breaks so badly it isn't worth repairing or B) one of Dynon Garmin or STEC decides to make available a digital AP.

Glad to help.

Just to be clear, my new copilot's panel is a clean sheet re-do, not an overlaid cover. Another thing to be sure of is the allowability of a panel material other than the original material. My original panel was made from a .050 sheet of 2024 T3, so that's what I went back with. My IA at one point made a comment the panel was "structural" which led me to believe that there might be specific requirements for the composition for the panel's material. You should check that out if you're thinking of changing material for your new panel's construction.

Here's a picture of the old panel prior to removal:
Old panel, installed

This is the picture of the old panel:
Old panel, removed

This is what was behind my old panel, after its removal: Note the brace I was talking about directly above the "FWD PASS AUX AIR" switch. Note as well, where my IA located the forward engine's EDC and sensors against the sidewall.
Behind old panel

I don't have the CNC file. I worked with a great guy locally who has all the equipment, and expertise, to do the layout, testing and cutting. If the frame of your copilot's panel is the same as mine (or at least close to mine), there might not be too much adjustment for him to layout and cut yours also. There, of course, would be some shiping back and forth until you got it the way you want it. He also, made all new placards and labels for the interior and made a new "Red Ball" for the handle of the emergency gear pump shaft, as mine appeared to have been broken into several pieces and glued back together several times. All of it looks great! We are working on new labels for the circuit breaker panel now. I'll put a photo below of this work in progress, but you'll be able to see the direction we're headed. His pricing has been very reasonable. I can get you in touch with him if you like, PM me and we can set a time to chat about his work, his contact info and all the options for you to consider in configuring your systems.

Work in progress on circuit breaker panel

Rick

Panel upgrade
 

Redoing our panel in 58C.

Looking to get as much input from others experiences as possible.

After about 5 tries we are almost there with the adjustments needed to get it just right.

Going with EI instruments as a primary replacement on the pilot side.

Will post pics in the morning

Are you doing the CGR-30P? If so, we should talk (and I would love to fly up from San Diego and see the project!). In addition to my 337 project, my brother/parents have a 337D and want to put a CGR-30P combo into it. Unfortunately, EI hasn't done an STC for us. Are you using a DER? Any chance you could share his info with me? I think I prefer the round gauges over the square (and significant panel mods required) for the mvp-50p.

EI product.
 

Did quite a bit of research and the EI product is well respected.

We are based at the old Norton air base would love to show you what we have done so far.

Still trying to upload pics maybe I can post a link to google drive of our progress.

Last iteration of the panel cut should be done next couple days.

Went with dual Aspens, kept the 400 autopilot which was sent out to Bevan for inspection / 8130.

Our plan is to have the 3 displays from EI on the pilot side where nav indicators used to live.

Feel free to contact us.

213-308-7077

Will keep updates going here for others to read.

Thanks

New link for all to see
 

Where did you put the other CGR 30-p? Any chance of seeing the major alteration FAA form and supporting data for getting it approved? Want to head down this same path very soon.

EI instruments
 

Still working on the layout.

No paperwork completed yet

Just got all the instruments situated last night.

Attaching pics after I create the link.

Thanks