I want to confirm or update my understanding of working on Exp (specifically, EAB) aircraft.

I believe when it comes to Exp, anyone can repair or modify such an aircraft.
No certifications needed. It could be the builder; subsequent pilot-owners; a welding shop employee; an auto painter; a carpenter; anyone, period.

The caveats are that-
-ALL work must have a correctly done entry in the aircraft maintenance records.*
-if the work changes the flight characteristics significantly (ie Major Modification) or operating limitations , it requires a return to Phase 1 testing.
-The 12-mo condition inspection can only be performed by the person with the Repairman’s Certificate for that aircraft, or an A&P.

*I can’t find a reference stating who can make this entry; can it be the pilot-owner who oversees the work, if he has not done the work himself?

Do Major Repairs require anything unusual such as certifications to perform work/ inspection/log entry/return to Phase 1?

Unusual? I can't think of anything. Other than maybe something like a transponder/pitot/static check. I assume those require some type of certification.

Unusual? I can't think of anything. Other than maybe something like a transponder/pitot/static check. I assume those require some type of certification.

This is actually not entirely clear for an E-AB. There are a handful of regulations that definitely do apply to E-AB that require recording in maintenance records, but it's less clear there is a blanket requirement in all cases (and it somewhat depends on the exact wording of the operating limitations). https://www.kitplanes.com/aircraft-reco ... -logbooks/ is a good run down of the relevant regulations.

(I would, of course, make the entries anyway, and do on my E-AB).

There is definitely no requirement for an A&P to do an inspection following a repair or modification of any type. Most A&Ps (and also most A&Ps with IA, most CFIs, most DPEs, and even a fair number of FSDO ASIs) don't know much about E-AB rules.

I still do some work on EAB's I built and carry the repairman's certificates. Mr Johnston's post above is correct. I continue to help train two AP's that are now the primary maintainers of the planes I built; they know much more than I do ...BUT not about the the specific plane. 3 of the EAB's I built were variants of a LongEZ, but the 3 are very different, and even a builder of another EZ might or might not be able to figure out what I did and why.

The issue of Major repairs is interesting, and in my experience is subject to FSDO interpretation. An example: after one highly modified EZ I built went off the end of the runway and tore the main landing gear bow of the rear of the plane...ten years after i sold it. I outlined the work, developed the layup schedules, supervised the repair and then contacted the local FSDO to see how they wanted to handle what I considered a major repair as the main landing gear ties loads to the centersection spar and engine mount primary structure. The FSDO asked me a couple of questions, I showed them a few pictures and they said it was fine and go ahead and release the plane to the owner. This plane was completed long before there was a Phase 1, so no changes to the operating limitations were made.

On a second EZ I built, 20 years after new ownership, I removed 10" from each canard tip, and altered the canard airfoil and elevator profile. This time the same FSDO, but different inspector required all new operating limitations and it had to return what the FAA was now calling Phase 1. In both instances, we did an annual condition inspection and at my insistence had the the AP sign the work and inspection, as did I using my repairman's certificate number.

At this point in my life, I will continue to assist the new caretakers 4 of the 5 EAB's that rolled out of my garage remaining on the FAA's register, but will no longer sign-off the annual condition inspections. Having been dipped in the legal system involving a very famous musician who perished in an EZ, I want to step away from the liability bucket as best I can.

You are correct. The original builder made the repairs and signed off the entry in the logbook. The aircraft is good to go. There is no requirement for an A&P (or anyone) to inspect anything.

This is my $0.02 -
If you have AOPA Pilot Protection Services - Call them. If you don't - Get it first thing tomorrow and make the call before all y'all finish the repair or sign-off. I still fly with friends and CFIs, though my medical is dead for 4 more years (recovering from pancreatic cancer), and carry it just in case. It's cheap insurance.

If not, there are plenty of good pilot attorneys on here that may consult for as little as an hour. Here in Northern Virginia that is $495/hr well-spent. Ergo, why I suggested AOPA. Also, I believe AOPA negotiates a discount for time past covered hours but that may have been an old benefit.

I have AOPA legal services plan...but I think I'll save that for a more dire situation. (I'm not even signing this off)
If I call anyone, I think EAA would be best.
Thanks!