Sorry, but this exact profile is no longer made. Others have replaced with plastic, wood or another aluminum extrusion that is close but not the same. The replacement aluminum extrusion was not close enough for me so I tried to get others interested to see if we could get a group purchase from a custom extruder but no one responded. I sold my boat so I no longer have a need for that rubrail.
You should be able to search the archive using the term "rubrail" to see how others handled this.