As others have stated, ACA has a repair station on site at the factory. In addition to servicing aircraft under warranty, they provide inspections, repairs, upgrades, parts, tech support, and restorations for ACA aircraft and predecessor aircraft from Bellanca and Champion that they are the TC holder for.
Having a factory annual done before listing for sale would be a great way to bump the value and maybe skip the pre-buy.
It is common for owners doing restorations to send the bare frame there for inspection, repair, and update to current specs. The repair station gets enough work that they are backlogged almost a year on restorations. Replacement wings are even further out.
It's a shame other manufacturers cannot sort out the legal issues. It is a HUGE plus as an owner to have this resource. Any possible problem that the type can have, they have seen dozens of times, and usually have the fix on hand, often as a kit that they will install or ship with instructions.
Some commenters may be over-simplifying the liability issue. Which manufacturer is better positioned to defend themselves from liability: one that makes active efforts to improve the safety of the older fleet, or one that won't touch anything?