Iconoquest by Smokey Springfield is book one of the Stinkweed Chronicles:
The End is nigh! The Evil Eye is wreaking havoc across the Realm sacking temples, looting altars and murdering tribesmen in search of an icon with miraculous powers. But the icon is lost – not in the sense it will turn up in a day or two, it is lost to myth and imagination.
With the city of Skirm next in its path, Hochwurzel Stinkweed Esq, hapless shyster, and his partner in crime Gerritt Muggins whip the city folk into a frenzy then flog them ‘magickal amulets’ which Hochwurzel personally guarantees will prevent the carrier from being burnt to a crisp by this evil entity.
For the first time in their miserable lives Hochwurzel and Gerritt are coining it in but their luck is running out. Unrest in the city is rising, General Lawkland Eldroth; Commander of the Lawkeepers of Skirm is losing control and determines to stop them trading – permanently. With Eldroth breathing down their grubby necks they encounter the legendary Blackguards, a notorious gang of thieves who want to know who is working their patch. This encounter takes them within fortunes grasp but also to the brink of death. Illustrated by me Barrie James