I have this model of Carver Riviera #2807. Mine is equipped with Mercruiser 230 HP twins.FW cooled.
With regards to engine access, I agree that in the original conformation of the cockpit seating, engine access is laborious. What I did was to remove the large fiberglass box on which the helm seat is attached. I installed a pedestal base on the engine hatch on to which a 26" pedestal is attached and in turn the original Carver helm seat. The removal of the seat and pedestal (remove 3 allen cap screws) takes less than 2 minutes allowing for quick access to the starboard engine. I should note that port engine access for the purpose of changing filters (oil and gas)checking oil, winterizing etc. is easily done since when the hatch is removed, there is more than enough room under the secondary floor on which the companion (dining) seat is located. These engine hatches are not hinged, but rather slide out of the way. I suggest that there are a lot of boats that are more troublesome as to engine access than Carver Riviera, certainly mine.
Now if someone can find me a hardtop like that shown on this forum topic photograph,I will be really happy. Carver no longer can supply and my efforts to find one have been unsuccesfull.