D&J, I just finished mounting a new side folding mast on my 2007 EC21.It was easy. Ceiling has to be let down inside,If you have the fake stack and raised center piece that the horn & spotlight are mounted on? There are 6 pre dimpled dents on this raised area -where the 6 bolt holes will be drilled! Kudah for the factory--thinking ahead!Ck and double ck them in reference to the holes in the mast mounting plate--mine didn't match--line up.Set the plate in place and get as many as you can to match and disregard the others.The front ones are the critical ones--forward to the back of the horns. Make sure you use those and let the others fall where they may.Get the mast thru Richard Ranger Tugs.Have him ship it to you. It would have cost me more to ship it from BC then the cost of the mast !!!! Richard will set it up with cables,mast light socket and all you need to install it. You will need to remove your socket anchor light ?? 2006 ?? Drill a new hole(1-1/8") in the fake stack.Install new plug--don't forget to put the rubber boot on with it--boot covers socket when the light is unplugged.You may have to add wire to existing to reach the new plug?? My light had 2 wires white & ?? White to white and it worked. Make sure your hatches are open when the cables are installed--need clearance so ski-lite doesn't rub on cables when open --Oppsss! Design note: Hard to explain--the raised cap that the horn,light and future mast bolt to ,has no clearance for the wires running under it! I put 1/4" plastic plates/shims in 3 places so the wires would not be pinched when the cap is reinstalled.The factory does not suppy any type of support/brace to hold the mast when in the fold down position. You need to order the fittings so they can install them with the mast. My mast is off and in the shed and I'm 50 miles away from the tug.I'll get you some pics when I get down there-maybe this wk-end. I have some pics I got from Rich of his support/brace.He used 2 braces.I'll attach those,so you get an idea I decided to go with one and it works fine! Cheers RB