Thanks for the compliments!
I managed to do a lot of work on the boom. All 4 sections are ready and the boom head is almost ready. Next is the telescope mechanism. I think it is going to be a variation on the single cylinder system.
I put it all together and tried it out. Here is a short clip:
http://www.youtube.com/watch?v=CgFCE_C24eM
Kerst