As CyberJack has said, you could go with swing-back blades, but that would be a bit self-defeating, I'd think.

After all, this thing is a slasher for hacking into weeds and rough stuff, not a lawnmower!

So either a one-piece bar blade, as the Mobilco Heavycut had, or a replica of the triangular plate/knife segment design used by Whirlwind would be the go.

The 'knife sections' are available, as grain headers all use the sickle bar cutter system.

This mob have a large range of bar blades, if you should decide to go that way. http://www.asproducts.com.au/index.php

New Heavycut blades are available from http://www.heavycut.com.au/SpareParts.htm
I can't recall offhand, what the exact cut width of the Heavycut machines is, but Heavycut Spares will know.

Cheers,
Gadge

"ODK Mods can explain it to you, but they can't understand it for you..."

"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."