Stu - interested if you get a source for McLeods, will email you.
Brash stays green for a while (depending on tree type) and then browns / looses bulk and is much easier to handle. I'd give it a while (if you have that luxury). At Stainburn FE came back in and mounded a lot of it up then set slow burning pyres to get rid. Sort of succesful.
Ground underneath is often trashed and more importantly the drainage is usually knackered. Water will route down vehicle tracks and just generally does what water does. Worth carefully looking at to decide whether to reclaim or relocate.
I'd take the opportunity to do both and make the most of the land now that you have to do lots of work to recover trails, rather than following the pre-existing lines (unless they were already the best).
Scruff - the prob with that Macleod is the bolt on the bottom. It'll either come loose, get spanged up ot make tamping / shaping harder with that lump in the centre of the plate. McLeods are good but my two favourite tools are proably Chillington Style hoes (or azadas - http://www.get-digging.co.uk/tools.htm) and long handled (fibre glass) shovels (swan necks / bull nose)http://www.toolstation.com/shop/Hand+Tools/Landscaping+Tools/Fibreglass+Handle+Round+Point+Shovel+48+Straight+Handle/d10/sd2669/p44025
A McLeod will be pretty poor for clearing the brash itself (although I suspect you meant for digging the trail beneath once brash cleared). Brashing hooks (especially long handled ones) are better but TBH it's just a PITA job. Plus sharp tools = less fingers, sooner or later
Common or garden pruning saws are excellent for getting through green wood fast. Chainsaws on FE land, without the proper tickets, are a one way trip to falling out with the Forest Manager IME.
We've got the same sort of job ahead of us at Norwood / Stainburn. We've improved the line that we will "reclaim" to make the most of the opportunity. It's not hard and fast though, different sites, levels of disturbance, etc etc mean the solution is likely to be unique to you. Not least will be the number of volunteers / their productivity.