Thanks for the comments
In terms of drilling the vent holes - the best option is a router.
I (stupidly) replaced it with MDF - should have used ply. Cutting a neat hole in MDF i found quite tricky - a holesaw seemed to push a few chunks out the back side of the MDF, as did a brad spade bit. I ended up drilling small pilot holes for the tip of the spade bit (32mm - a bit smaller than the standard size) and cut from both sides - i didn't try going from both sides with the holesaw but probably should have. The holes are OK, but not perfect.
I reused the old earth braid as it was OK, i couldn't find the original size staples locally, so just got a manual $20 staple gun from bunnings and the staples are probably 10-13mm i think, a bit wider than the earth braid. It would be nice to have an air stapler as the manual one doesn't get them right in all of the time and i need to tap them a bit with the hammer
