The twing system was just about as popular as the track back in the 1980s, but not many use it today. Mackay still offered it when I last looked at their order form a couple of years ago, but it's not there anymore. The padding/risers on your lead blocks are very likely homebuilt, though.Is that how MacKay outfitted their boats? I believe this hull is a mid '90's build.
Your pole was made by (of course!) Goldspar of AustraliaThat gold spin pole is what I have, haven't found the end fittings though, I ordered a pair of Selden fittings from Mackay but they were too small.