New rivets on end of boom swivel?

[dingusdingo]

ibb.co/2tdQbtp

HEy! ABout to start my trip down some of the Norwegian coast next week and am going through some final things on my 27. Anyone familiar with the construction of this end cap thingy on the end of the boom? I see the rivets are currently corroded so I was thinking drilling new holes a few centimetres away and leaving the old ones. Am I going to drill into anything unwanted? I am worried about drilling the existing ones out and not being able to secure it properly again... also, does anyone know what thickness and length rivet I would need?

also, I need to swap out a wire on the right side of my rigging. Do I need to loosen all the side rigging or can I just do the one, or a pair on each side?

TIA,

Dan 

[dingusdingo]