I bought a slow build wing and fuselage kit at different times with the fuselage kit packed May 2015 - fairly recent.
The center section ships with the fuselage kit not the wing kit and comes in a bag as two halves separated by foam. The web and bars are already riveted. You have to add bulkheads, seat brackets and rivet the two halves of the center section together.
Center section out of the box
I had one minor panic building my center section. Both the spars and center section are numbered. Those numbers must be important, right? But the spar and center numbers do not match. Would my spars fit the center? Of course Vans was closed for the night.
Next morning tech support assured me that Vans does not ship matching centers and wings for the RV-8. Years ago before the pre-punch kits they shipped center sections with the wings. Now the tooling is so accurate they ship the center with the fuselage kits and parts will fit even thought numbers do not match.
In fact there is no way to get a matching set of numbers. To support that Vans would need to keep center sections lying around for years waiting for builders to complete wings.