OK Mike, thanks for that, always better to be talking about the original and not an interpretation.
It looks like the builders of the MM model got either the bow & stern mixed up or someone put the oarsmen in the wrong way round.
If those are oarsmen on the original then they look very strange to me, no part of a normal rowing stroke has the arms & oars in that relative position but it doesn’t look quite right for paddlers either. The paddlers are the best interpretation because they can’t possibly be oarsmen unless you just assume the artist got it completely wrong.
Looking at the lower ship, the stern ‘thing’ seems to be a solid piece pivoted near the steering oar and with two rope ladders or similar holding it up. My best guess is that it is a loading ramp that can be let down to a beach for easy access to the deck.