Hi Greg

I use a Pacer / Old Paper tiger/ Sabre section.

You can get a cut length or full lenght from Keeley Marine Supplies
Section Code: K02
These Sections are not Anodised

Alternative cut the track off a cut down mossie mast or current PT mast.

You can get tubes e.g. 50mm. i personally don't like as i like to make an outhaul that slides easy inside the boom. On a round section you basically rig up outhaul same as a laser with a dyneema strop. Sometimes they don't like sliding along the boom.

Im making 3 booms in the next 2 weeks. I also make the outhaul cars. Ill post pics later. I have a 3mm 50x40mm in a egg shape, with 1 x 8mm rod welded through the bottom with a 25mm nylon wheel on each side of the plate wide enough to hit the edge of the section. (no captive pins to hold wheels on).

I have a block on the outboard end of the plate ( Greg can post pic) as its a 2:1 system.

Matt