This rep is very easy to get to max ally. Just repeatedly do the 3 tasks at the farm you get from the camp nearby, from Sigglik, in Dragonscale Hills. I wouldn't reccomend any less than level 68, maybe 70, doing this without a group.
Farm Clean Up - Crows - Kill 12 Crows.
Farm Clean Up - Doombugs - Kills 20 Doombugs.
Farm Clean Up - Scarecrows - Kill 10 Scarecrows.
It took me around a week to get max faction with them, so its easy just takes some time. The mobs that you kill don't hit hard at all, and they drop a lot of vendor stuff that will make you a fortune in the mean time.
To check your rep, go to the cannon that takes you to Fort Mech, and in that camp pretty much all of them (I would suggest conning the suppliers, they seem to work) work for considering for your rep.
Hope it was useful. :)