Looks a beauty -- nickle-plated copper? Or stainless?
What you have circled are the heat exchangers which--judging by the angle of the photo at least--- appear to terminate directly into the groups without a reduction. I cant say Im familiar with that.
Normaly the exchangers connect with the groups through much smaller pipes, whose size and length "tunes" heat retention in the groups.
Why do you say its a long-term project? Does it need much work?