Check out www.drsa.com
and look for fixtures labeled Mako or Cayman Broc (or maybe that's Brac). The trim rings and lenses may not actually look like what you have, but the fixture itself does, sorta kind,a from your pics. And then if it's near enough but not exact, they may have other models that actually match what you're after.
I suggest them because they've been very helpful to our owners club.
Then check our www.marinebeam.com
and look for G4 bulb replacements. Their Force 12 (12-diode) warm white replacement discs are excellent. (Their 10-diode "X-Beam discs are OK, too, but I recently replaced a bunch of G4 halogens on dimming circuits and also several elder LEDs on non-dimming circuits, and found the increased lumens from the 12s suited our situation better.)
In our case, I did not have to replace fixtures; it was a simple bulb (disc) swap.